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Coyote and Quail Focus on Coyote and California Quail Mt. Diablo's Other Inhabitants! by Keith Patterson Reprinted from the Mount Diablo Review , Fall 2000 The Coyote (Canis latrans ), a member of the dog family, is native to California. It closely resembles a small German shepherd dog with the exception of the longer snout and bushy, black-tipped tail. The coyote’s high-pitched, yodel-like yapping can frequently be heard at night. Coyotes are extremely adaptable and can survive on whatever food is available. They hunt rabbits, mice, birds and other small animals as well as young deer and sheep. They will also feed from the carcasses of dead animals and will accept handouts from people in the form of table scraps, pet food and garbage. Coyotes are found throughout California, from deserts and mountain habitats to urban areas. They have certainly become much more common on and around Mount Diablo in recent years. Problems occur when people begin feeding coyotes, either deliberately or inadvertently. Coyotes will quickly lose their natural fear of people and become bold, even aggressive. Pets are sometimes injured or killed by coyotes. Coyotes on Mount Diablo tend to live alone or in breeding pairs. Alone, in pairs or in packs, coyotes maintain territories by marking with urine. They also use calls to defend territories. Several solitary males may gather to court a female at the start of the mating season, but the female forms a relationship with only one of them. The mating season extends from January to March so that the pups are born in spring when the food is abundant. The pups are born blind in a natal den. After about 14 days their eyes open and they emerge from the den a few days later. The pups suckle for five to seven weeks; at three weeks they start with semi-solid food regurgitated by both parents. At the end of the summer they can care for themselves and may leave or stay with their parents, depending on food availability and habitat conditions. If you happen upon coyotes on the mountain steer clear of them as much as possible and vacate the area as soon as possible. If they approach you, and only if, make loud noises and wave your arms to scare them away. The coyote is one of the fastest mammals in North America, reaching speeds of up to 38.4 mph. Coyotes can breed with wolves and domestic dogs. A dog-coyote mix is called a ‘coydog’. Many Native American tribes consider the coyote a maker of fateful decisions with the power to transform beings and objects. The California Quail (Callipepla californicus ) was selected by the State Legislature in 1931 as the official state bird of California. Sometimes called valley quail, this gallinaceous (chicken-like) bird is widely distributed over approximately 70% of the state where suitable habitat remains. It is one of the most popular upland game species enjoyed by sportsmen (although not on Mt Diablo) and birdwatchers alike. The quail prefers nesting in woodland-brush areas interspersed with grasslands. When not nesting or brooding young, California quail roost in tall bushes and trees at night. In late summer, fall and winter family groups may join together, forming coveys of 50 to 100 birds or more. In early spring the coveys break up into pairs and look for suitable nesting sites. The species is monogamous; the male takes only one mate during the season. He is a very attentive mate, for he will assist in the incubation of eggs and in the care of young. He is also an alert sentinel warning his mate and young when danger approaches. The nest is usually constructed on the ground in a shallow depression lined with grass, and is under some protective cover such as a bush, log or weeds. The average clutch size is 10 to 15 creamy eggs that are lightly spotted with golden brown although there has been a tendency towards lower clutch sizes in this area in recent years. The incubation period is 21 to 22 days. The young are ready to leave the nest shortly after drying off. The diet of California quail consists mainly of seeds during the dryer seasons and greens in the winter and spring. The chick’s diet is composed of insects, greens and seeds until they are several weeks old, at which time their diet becomes similar to that of the adults. The California quail is very vocal. When birds are busy feeding, a number of different calls may be heard at close range. A scolding call is often given as birds scurry from danger. The year-round assembly call is most commonly heard and is a loud, clear "cuc-ca-coo". It has been interpreted as "chi-ca-go", "come-right-home", "get-right-up" and many other expressions. During the breeding season from April to July, the male, perched on a post, repeats at intervals a single resonant note. The large flocks post sentinels to danger. Photo credits - Michael Evan Sewell (Coyote) and Dave Furseth (Quail) Some of the information for both these descriptive pieces was taken from California Department of Fish and Game literature Back

Great Copper Lycaena xanthoides Lycaenidae Blues, Coppers, Hairstreaks Flies April to October Host Plant Dock Nectar Plant California buckeye, Gum plant Hank Fabian Underwing Hank Fabian Female Hank Fabian Male

A History of Mt Diablo Prepared by Seth Adams, Director of Land Programs, Save Mount Diablo Reprinted from Mount Diablo Review, Fall 2000 History of Mount Diablo Geologic Summary: 165 million B.C. Mount Diablo began as volcanic rock beneath the surface of the Pacific Ocean was scraped into a mass between the Pacific tectonic plate and the overlying sedimentary layers of the North American plate. As ice ages affected sea levels, sedimentation continued in shallow coastal seas. About four million years ago, the older, harder volcanic material from the sea floor forced its way up from between the two plates heaving the weaker sedimentary layers up an angle. Over time, younger rock above eroded and by 2 million B.C. the older rock we recognize as Diablo's peaks was exposed as low-lying hills. Human History: ca. 2000 B.C. According to one tradition, at the Dawn of Time, Mount Diablo and Reed's Peak were surrounded by water. From these two islands the creator Coyote and his assistant Eagle-man made Indian people and the world. In a Plains Miwok creation account, Mol-luk (Condor man) lived on the north side of Mt Diablo. His wife, the rock on which he roosted, gave birth to Wek-wek (Prairie Falcon-man). With the help of his grandfather Coyote-man, Wek-wek created Indian people, providing them with "everything, everywhere so they can live". March, 1772 Fages-Crespi expedition. Lt. Pedro Fages and Father Juan Crespi explored the Carquinez Straits and the western side of the mountain into the San Ramon Valley. In 1782 they returned to the mountain, climbing to the summit. 4-1/3, 1776 de Anza-Font expedition. Juan Bautista de Anza and Father Pedro Font conducted a second expedition circling the northern part of Diablo from Pacheco to present-day areas of Concord, Antioch and Byron. The de Anza expedition included Juan Salvio Pacheco whose grandson, Salvio Pacheco, founded Concord. 1800 Spaniards begin using Mount Diablo for winter grazing after the Mission San Jose was founded in 1797 (in part to more easily missionize East Bay natives). In 1819 from the mountain's slopes Lt. Jose Maria Estudillo wrote "The view from south to north is beautiful, for its end cannot be seen". Ca. 1805-1806 The naming of Mount Diablo. General Mariano G Vallejo, in an 1850 report to the Legislature, gives the derivation of the name of Mount Diablo from its Native American to Spanish to Anglo form. In 1806 Spanish soldiers were pursuing native Americans as part of the missionization, the natives took cover in a thicket near Pacheco and the Spaniards camped with the intention of rounding them up in the morning. During the night the natives escaped across the Carquinez Strait, an act only possible, according to the Spaniards, with the help of the Devil ("Diablo"). The thicket became known as "Monte del Diablo" and Anglo settlers later misunderstood that the word "monte" can mean "thicket" or "mountain", and fastened the name on the most obvious local landmark. 1822 & 1824 Spain ceded California to Mexico, the Mexican Revolution took place and the beginning of land grants , including 18 in what became Contra Costa County. Between 1833 and 1846 three Rancho San Ramon Mexican land grants established to Bartolome Pacheco (southern San Ramon Valley) and Mariano Castro (northern San Ramon Valley, two square leagues), and Jose Maria Amador (four leagues). 7-31-1834 Ranch Arroya de las Nueces y Bolbones or 'Rancho Miguel' 17,782 acres were granted to Don Juana Sanchez de Pacheco including Pine Canyon, Little Pine Canyon and the North Gate Road area, Diablo and Turtle Rock Ranches. Approximately ¼ of the land grant is within the State Park today. 1837 Dr John Marsh, "Brentwood". Dr John Marsh, Contra Costa's first American settler, acquired Rancho Los Meganos from Jose Noriega of San Jose, approximately 13,285 acres for $500. c. 1835, Marsh's stone mansion (John Marsh Home) built at his rancho; the home is named "Brentwood' for his ancestral lands in England. Marsh was killed before the home was completed. 1841 The first travel account of Mount Diablo Eugene Duflot du Mofras – French attaché to California. By 1846 American immigration to the area had begun. 1848 Coal reported in CCC and on 1-24-1848 Gold was discovered at the American River, leading to rapid population increase in California. 1848 Treaty of Guadalupe Hidalgo. Alta California becomes American territory, and much of Mount Diablo, sobrante lands bounded by Spanish land grant ranchos, was designated public domain and for homesteading at a minimum price of $1 per acre. In 1849 Frances E. Matteson came to California and homesteaded 160 acres which later became part of the Blackhawk Ranch. He hunted deer, bear, elk and antelope. Ca. 1850 Morgan Territory. Jeremiah Morgan moved form the Ygnacio Valley to unsurveyed public land on the east side of Mount Diablo, ca. 1850, because the grizzly bear hunting was so good. Francis Such and W. E. Whiting discover lime on the northwest foothills of Mount Diablo on what becomes known as "Lime Ridge". 4-1850 Naming of Mount Diablo. General Mariano Guadalupe Vallejo, in a Constitutional Convention report to the State Legislature, discussed the naming of Mount Diablo. "It was intended to call the county (Mount Diablo), but both branches of the Legislature, after warm debates on the subject, resolved upon the less-profane one (name) of Contra Costa. (Including present-day Alameda County). (Also see article on name change request and denial) 1851 Mount Diablo meridian and survey. Colonel Leander Ransom, Deputy-Surveyor General, established the initial point of the Mount Diablo meridian at the mountain's summit, beginning the survey of public lands in California. The hills north of the Clayton area became known as the meridian Hills (the ridge between Concord and Pittsburg). 1852 The US Coast and Geodetic Survey used Mount Diablo as a base point for its National Triangulation Survey. Walnut Creek's population is less than 50. On 5-18-1852 Alamo (Spanish for "poplar" or "cottonwood") is designated and a post office established on the northern Rancho San Ramon. 1857 Joel Clayton, an English immigrant, founded Clayton. In 1859 coal is discovered north of Clayton. For a time it is the chief source of fuel for manufacturing on the west coast. The two towns of Somersville and Nortonville ultimately included about 1,000 residents each and became ghost towns around 1885. 1860 "Almost every Californian has seen Monte Diablo. It is the great central landmark of the state. Whether we are walking in the streets of San Francisco, or sailing on any of our bays and navigable rivers, or riding on any of the roads in the Sacramento and San Joaquin Valleys, or standing on the elevated ridges of the mining districts before us – in lonely boldness, and almost every turn, we see Monte Diablo". J.M. Hutchings, from Scenes of Wonder and Curiosity in California . Bret Harte and the Legend of Monte del Diablo. Farmer Abner Bryant hired a tutor for his sons on his Sycamore Valley farm (on the present-day Blackhawk Ranch), the first job for future-writer Francis Bret Harte (lived 1836-1902). Harte later wrote the most widely-reported myth regarding the naming of Mount Diablo, "The Legend of Monte del Diablo". 1861 Whitney's California Geological Survey visits Mount Diablo. William Brewer wrote "The region north and northwest of Mount Diablo is a beautiful one – pretty valleys scattered over with oaks, many of enormous size, with wide branches, often dropping like the elm. The rugged mountain rises against the clear sky, and when illuminated by the setting sun is an object of peculiar beauty. Our camp was in a very pretty place, with great trees around, and the mountain in full view." The Survey gathered rocks, fossils and plants (including 25 plants not then known and measured the mountain's elevation at 3,890 ft. 4-30-1862 Description of View, Mount Diablo elevation. Brewer estimated that the view embraced 80,000 square miles, 40,000 "in tolerably plain view – over 300 miles from north to south, and 260 to 280 miles from east to west". The view includes 60% of California, 35 counties and an area equal to the six New England states. Brewer's party calculated the height of Mount Diablo at 3,876.4' (actual 3,849'). 1863 Major drought throughout California, many county residents survived by working at the lime quarries. Copper ores with traces of gold were found in Mitchell and Bagley Canyons, at Eagle Peak, and there was a short-lived copper and gold rush. In 1863-4 L.W. Hastings discovered quicksilver (mercury) on the northeast side of North Peak and Perkins Canyon was mined until the 1950's. 1865-66 Legislative attempt to change the name of Mount Diablo. The State Legislature made an unsuccessful attempt to change the name of Mount Diablo to "Coal Hill'. Clayton resisted the name change. 1870's The Green and Sycamore Valleys are well-populated, most of the southern area is used for thoroughbred horses (until WW1), as was Perkins Canyon. In 1873 William Cameron began buying land in Green Valley. Several railroads also began purchasing land, and in time a single owner of the "Big Four" emerged, Central Pacific Railroad, which appointed David Colton (died 1878) to manage the 10,000-acre "Railroad Ranch". He was given Mark Hopkins share, and in time bought out Crocker, Huntington and Stanford. First Wagon Road up Mount Diablo and the Mountain House Hotel constructed. Green Valley and "Mount Diablo Summit Road Company" incorporated to build the first toll wagon roads up the mountain, by local investors including Cameron and Joseph Hall, who also built the 16-room Mountain House Hotel a mile below the summit (operated through the 1880's, abandoned 1895, burned c. 1901). In 1874 Seeley J Bennett inaugurated a stage line from Martinez to the Diablo peak, by 1879 including hundreds of visitors a year. Kate Nevins, who had worked at the Mountain House wrote "Citizens from all over the state made pilgrimage with wagon loads, journeying to the Mountain House then hiking to the observatory at the top. They stayed sometimes for weeks to enjoy Pine Canyon, one of the finest beauty spots on earth with its magnificent views of the Castle Rocks." 1876 The US Coast and Geodetic Survey erected a three-story signal station at the Summit, which was later equipped with a telescope by Joseph hall for the use of Mountain House guests (it burned 7-4-1891 when fire swept up from Morgan Territory). Hall also had a floored tent at the summit for guests who wished to sleep there. 1877 Cook Farms, Oakwood Park Stock Farms. Colton's daughter Caroline and her husband, mining engineer Dan Cook, inherited the Railroad Ranch, which by then extended from Green Valley School to Sycamore Valley and to Curry Creek, taking in the headwaters of Marsh Creek, the southern summit road and the Mountain House Hotel. Brothers Dan and Seth Cook (both 'rough, obscenity-speaking and hearty fellows' according to R.N. Burgess) and changed the name to Cook Farms. Seth, a bachelor, inherited and passed the farm to his niece Louise and her husband John F. Boyd. Boyd renamed it the Oakwood Park Stock Farms and by 1897 it included 6,000 acres. By 1913 it grew to 15,000 acres, including areas of Dan Cook Canyon, Rock City, Devil's Slide and the area along South Gate Road, and was considered the largest stock farm in the world. 1879 Concord had a population of 300 and in 1880 the village of Walnut Creek included about 300 people. Over the next decade major fired scarred Mount Diablo, reportedly started by careless hikers and campers, leading to landowner calls to close the mountain to the public. 1890 John Muir, one of the founders of the American Conservation Movement, moved to Martinez, until his death in 1914. By the 1890's grizzly bear and great herds of elk had disappeared from the area. Sunday picnics were often held at Mitchell or Pine Canyon. William Cameron died and his daughter Kate McLaughlin Dillon sold off her father's holdings, including White Canyon and Deer Flat to Dominic Murchio, an Italian immigrant with a ranch alongside Mitchell Creek, including part of Mount Zion. "Clear and cool. Beautiful silvery haze on Mount Diablo this morning, on it and over it – outlines melting, wonderfully luminous." - John Muir, 1895. 1899 Borges Ranch established at Shell Ridge. Frank Borges buys 700 acres (now preserved within Shell Ridge Open Space). Designated on the National Register of Historic Places in 1981. 1900's Contra Costa included 18,000 citizens at the turn of the century, 645 in Concord. The County includes 900,000 today. During the county's first decade, President Theodore Roosevelt ushers in a first wave of American Conservation. 1903 First tunnel through the Oakland Hills (now Old Tunnel Road). The tunnel inaugurates waves of new residents. In 1904 public electricity is established locally and in 1907 the first automobile garage. 1907 The Henry Cowell Lime and Cement Company moved to the Diablo Valley at Lime Ridge and built the town of Cowell, employed 250 men, ran 24 hours a day (part of the area is now preserved in Lime Ridge Open Space). 1911 First electric train extended into the County, the Oakland, Antioch and Eastern Railway through a 3,400 ft tunnel in the Oakland Hills to Walnut Creek to carry lime. Special trains ran for the R.N. Burgess Co., which sold land adjacent to the mountain at Diablo (June 2, 1914-1924). 1912 The Mount Diablo Development Co. established. Louise Boyd sold Oakwood Park Stock Farm to R.N. Burgess and his Mount Diablo Development Co., a group of investors who wanted to create an exclusive residential park. They remodeled Cook's Clubhouse/Casino as the Mount Diablo Country Club and opened Mount Diablo to the public. Burgess then acquired the area later known as Blackhawk Ranch and all the land between it and Diablo, up to the summit, including the right-of-way to Mount Diablo Scenic Boulevard. 1912-15 Mount Diablo Auto Toll Road. Burgess' group built new toll roads accessible to auto traffic all the way to Diablo's summit (North Gate and Mount Diablo Scenic Blvd – completed 1915). 1916 Castle Hotel planned for Mount Diablo Summit. Mount Diablo Development Co. planned a tower-hotel "Torre de Sol" (never built) with promised investment and national publicity by William Randolph Hearst. World War 1 intervened, Hearst's interest waned, Burgess' company went bankrupt and of the planned development only the community of Diablo was ever built. 1917 Blackhawk Ranch founded. Ansel Mills Easton (the uncle of the photographer Ansel Adams) and his son-in-law William A. Ward purchased 1200 acres from R.N. Burgess and started the Blackhawk Ranch named for a famous Irish race horse "Black Hawk" he had owned. Meanwhile, Portuguese immigrant Frank Macedo purchased 825 acres in what is now a park staging area in Alamo. 1921 Mount Diablo State Park created. Mount Diablo was one of the seven state parks created before the establishment of the California State Park System in 1927, a "state park and game refuge" on 630 acres (from Burgess' Mount Diablo Development Co.,) administered by its own appointive Mount Diablo State Park Commission. 1927-28 California Park Survey. Frederick Law Olmstead prepared a statewide survey (the Olmstead Plan) for the newly-created State Park Commission, recommending acquisition of 5-6,000 acres at Mount Diablo to "amplify" and "round out" the small state park at the summit. Major properties were acquired along the historic Scenic Boulevard (South Gate Road), the North Gate Road and near the summit. 1928 Standard Diablo Tower. Standard Oil of California constructed a 75 ft aviation beacon jointly with the U.S. Dept of Commerce to encourage and as a guide for commercial aviation (visible for 100 miles, first lit by Charles Lindberg). The beacon was later transferred to the Summit Building and is now lit only on 12-7 Pearl Harbor Day. 1929 Mary L. Bowerman, founder of Save Mount Diablo. A young student at the University of California and future co-founder of Save Mount Diablo in 1971, Bowerman begins research on the botany of Mount Diablo, culminating in a 1936 Ph.D. thesis and the 1944 publication of the recognized work on Mount Diablo "The Flowering Plants and Ferns of Mount Diablo, California". Dr Bowerman continues as an active member of the Board of Directors of Save Mount Diablo in 2000. 1930's CCC Era on Mount Diablo. The Great Depression and increasing calls for the municipalization of basic services ushers in the second wave of U.S. conservation, as public watersheds and parks are created. The Civilian Conservation Corps constructed Camp Diablo on the Danville side of Mount Diablo and built facilities at the mountain (among the best in the State's parks), realigning park roads, building hiking and fire trails, residences, picnic areas and campgrounds, dams and the Summit Building (1939-42). 1930 Proposal for the East Bay Regional Park District. Publication of the Olmsted-Hall Report "Proposed Park Reservations for East Bay Cities" supported a Committee of East Bay Citizens proposal to create the East Bay Regional Park District from surplus East Bay Municipal Utilities District land, recommending a 10-11,000 acre park system extending 22 miles along the East Bay hills above the nine Bay shoreline cities below. 4-20-1931 Mount Diablo designated a unit of the new State Park System. 1934 Establishment of the East Bay Regional Park District. In 1936 the S.F. to Oakland Bay Bridge is completed, and in 1937 the two-bore Caldecott Tunnel, making the East Bay and Central County much more accessible – the County's first major subdivision is approved that same year. Nobel Prize Winner Eugene O'Neill moves to Danville – "Mount Diablo, a mass of purple in the morning. Nature is always lovely, invincible, glad whatever is done or suffered by her creatures. All scars she heals; whether in rocks or waters or sky or heart." 1940's Population growth. The 1940's census reports 1,587 people in Walnut Creek, 1,373 in Concord. Camp Parks' Seabees (Navy construction battalions) established Camp Diablo, a base at Rock City to train in mountain warfare, road and bridge construction. At the end of the war development booms. 1960's Population growth in the Sixties. Contra Costa County population: 409,030, up 330,000 since 1930. Concord included 36,208 up from 1,373 in 1940. In 1966 much of Pine Canyon is added to the State Park. 1970's The Seventies – Environmental awareness and the first Earth Day usher in a new wave of conservation. Concord becomes the County's largest city. Traffic increases dramatically, General Plan process instituted as state law, the California Environmental Quality Act and the federal and state Endangered Species Acts. A proposal to develop Shell Ridge is defeated and local bond issues are passed to acquire open space in Walnut Creek and Concord. 12-7-1971 Save Mount Diablo founded. Co-founded by Art Bonwell and Dr Mary Bowerman. SMD was created because subdivisions were spreading toward the mountain, and no organization was working primarily on the area. Bowerman provided the organization's vision, while Bonwell was the nuts and bolts guy. Bowerman wrote "My dream is that the whole of Mount Diablo, including its foothills, will remain open space . . . that the visual and natural integrity will be sustained." In 1971 Contra Loma Regional Park was created. 1972 BART reaches interior Contra Costa County, adding to growth pressures; working with the State, Save Mount Diablo helps preserve the mountain's northern canyons (Mitchell, Back, Donner) over the next several years. In 1973 Black Diamond Mines Regional Preserve and the City of Walnut Creek's Shell Ridge Open Space are created. 1-1974 Mount Diablo Interpretive Association founded to work with the State Park in producing interpretive programs and publications. 1974 Blackhawk Development proposed. Ken Behring acquired 4,200 acres of the Ranch and proposed subdivision. Save Mount Diablo negotiated for 2,052 acres to be dedicated to MDSP as a condition of develoment, including much of the Blackhills – the Wall Point area, Blackhawk Ridge, parts of Dan Cook and Jackass Canyons, and the area below Oyster Point, the single largest donation ever to a State Park. 1975 Morgan Territory Regional Preserve is created. Concord population increases to 85,423 residents, up from 74,958 in 1966, 36,208 in 1960 and 1,373 in 1940. 1976 Save Mount Diablo's first acquisition with private funds, the Morgan Territory Investment parcel at the corner of Marsh Creek and Morgan Territory Roads, Lime Ridge Open Space is acquired and Diablo Foothills Park is created at Pine Canyon. In 1977 a large fire burns from Clayton to Blackhawk In 1978 Mount Olympia and the Mount Diablo waterfalls are acquired. 1980's The Eighties, growth booms. 101,844 in Concord, up from 85,423 in 1975. North Peak and Prospector's Gap are added to the State Park in 1980 along with Long Ridge and Pine Canyon, Emmons Canyon in 1982, White Canyon and Black Point in 1984. In 1988 Save Mount Diablo hires its first staff. In 1989 Save Mount Diablo's Morgan Ranch acquisition connects the State Park with Morgan Territory Regional Preserve. 1988 Round Valley Regional Preserve is created and in 1989 acquisition of the Los Vaqueros watershed and the Vasco Caves Regional Preserve begins. 1990 Senator Daniel Boatwright "Someday when Contra Costa is 4 million people maybe someone will say 'I don't know who did this but thank God for whoever saved this in the past. You won't be here. I won't be here. But the legacy we leave should not simply be that we passed everything over." 1996 Acquisition of Brushy Peak Regional Preserve begins. 1999 SMD's 427-acre Silva Ranch acquisition largely completes protection of Riggs Canyon. 9-25-1999 Mitchell Canyon Interpretive Center opened by Mount Diablo Interpretive Association working with MDSP. Informational sources: DPR, Edna May Andrews "History of Concord", Mary L. Bowerman "The Flowering Plants and Ferns of Mount Diablo, California", William H. Brewer "Up and Down California in 1860-1864", George Emanuel "Walnut Creek Arroya De Las Nueces", Virgie V. Jones "Historical Persons and Places… in San Ramon Valley", Bev Ortiz "Mount Diablo as Myth and reality; an Indian History Convoluted", George A. Pettit "Clayton; Not Quite Shangri-La", Nilda Rego "Days Gone by in Contra Costa County, California, Volume 1 & 2", W.A. Slocum & Co. "History of Contra Costa County, California", James C Stone "Diablo Legacy; Recollections & Reflections 1912-Present". Summit Visitor Center | Clayton Worsdell Find more information below: History Mount Diablo Name Origin Contra Costa County Name Origin Blackhawk and the Mountain Mountain House Hotel Uncommon Place Names The Green Ranch Exploring History of Mount Diablo Scenic Road History Summit Building Mount Diablo Initial Point Communication Tower Blown Over Mitchell Canyon Visitor Center Opens John Muir Slept Nearby Cultural Heritage Early Inhabitants Cultural Heritage of Mount Diablo The Miwok Park History Park Opens 1931 Ranching Barbed Wire Bonanza

Mountain Mahogany Hairstreak Satyrium tetra Lycaenidae Blues, Coppers, Hairstreaks Flies May to July Host Plant Mountain Mahogany Nectar Plant Horehound Daniel Fitzgerald Underwing Ken-ichi Ueda Underwing

Juniper Campground Map

Reservations Required Hike: Winter Solstice Saunter Sunday, December 21, 2024 Joyce Chin 9:30 AM - 12:30 PM Location: We'll assemble near the Mitchell Canyon Visitor Center. Let your inner Druid shine on a winter solstice nature hike up Mitchell Canyon. As we walk, we'll search for signs of the season, including mistletoe, beard lichen, Christmas berry, and those natural tree ornaments, “oak apple galls” and “California pears.” Who knows, we might even crash a ladybug slumber party! This is a moderate hike of 4-miles round trip with a slight elevation gain. You may opt for a 2-mile round trip hike. Bring snacks and water. Dress in layers and wear good hiking shoes. Bring poles if you normally use them. Rain cancels. Presented by California State Parks and Greenbelt Alliance Reservations Required: mtdiablohiker@gmail.com There is a $6 per vehicle park entrance fee ($5 for seniors). Exact cash required; pay at the entrance gate. You may also pay digitally by scanning the QR code on the sign near the entrance gate or Visitor Center; or text CA2902 to 53242. No app is required. Contact: mtdiablohiker@gmail.com Leader(s): Liz Watson and Ken Lavin

Brushfoots American Lady Vanessa virginiensis California Ringlet Coenonympha tullia California Sister Adelpha californica California Tortoiseshell Nymphalis californica Callippe Fritillary Speyeria callippe Coronis Fritillary Speyeria coronis Edith's Checkerspot Euphydryas editha Gray Buckeye Junonia grisea Great Basin Wood-Nymph Cercyonis sthenele Leanira Checkerspot Chlosyne leanira Lorquin's Admiral Limenitis lorquini Monarch Danaus plexippus Mourning Cloak Nymphalis antiopa Mylitta Crescent Phyciodes mylitta Northern Checkerspot Chlosyne palla Painted Lady Vanessa cardui Red Admiral Vanessa atalanta Satyr Comma Polygonia satyrus Variable Checkerspot Euphydryas chalcedona

Swallowtails Anise Swallowtail Papilio zelicaon California Pipevine Swallowtail Battus philenor Pale Swallowtail Papilio eurymedon Two-tailed Swallowtail Papilio multicaudatus Western Tiger Swallowtail Papilio rutulus

Golden Hairstreak Habrodais grunus Lycaenidae Blues, Coppers, Hairstreaks Flies Host Plant Nectar Plant Daniel Fitzgerald Underwing Paul G. Johnson

Geology Road Map Road Log Along Mount Diablo Scenic Drive and Summit Road by Roi Peers Southgate Road - Danville Entrance 0.00 (Odometer Reading) Set odometer to “zero” as you turn north onto Mount Diablo Scenic Blvd (South Gate Road) from Diablo Road or Blackhawk Rd. (see map) For the first half mile you will be crossing non-marine strata of Pliocene and Upper-Miocene age. The beds are almost vertical and you will be traveling 90 degrees to the strike of the beds, progressing over increasingly older strata as you proceed north past the Athenian School. These beds are the same age as those containing the Blackhawk Ranch Quarry mammal fossils. Up ahead you can see the light tan stratified rocks of the Eocene “Domengine” at the top of the ridge. 0.5 The rounded hills to the right with scattered oaks and newly built homes represent the transition from non-marine to marine in this area. You will continue for about four-tenths of a mile, past the first sharp turn to the left until you reach the second sharp turn to the left. 0.9 Here you take the second sharp turn to the left. Almost all of the maps show this as the upper boundary of the Neroly Formation . The Neroly sandstone and shale is brownish in color along the roadcuts and contains rich fossil clam beds, well exposed farther east in Sycamore Canyon. The material making up the rock is volcanic debris in origin, material eroded from an ancient Sierran highlands. 1.1 Boundary Gate to park. You will traverse eastward (and occasionally northward) and begin your climb up the south flank of Mount Diablo. You will continue to travel over increasingly older Neroly for the next one-third mile, expressed as rounded grass-covered hills with oak trees prominent. 2.1 Final turn north in the Neroly brings into view the steep—almost vertical—chaparral-covered slope of the Miocene Briones Formation just ahead. 2.3 As you make a sharp turn to the right, you will begin the serious climb up the south side of Mount Diablo, driving on the Briones Formation . The shallow marine sandstone beds are not only almost vertical here, they are in fact slightly overturned, which means the “underside of the beds” (facing south) is younger than the “topsides” (facing north). The beds frequently contain marine fossil shells. As you climb up the Briones “wall,” the difference in the character of the topography and plant communities between the Neroly and Briones formations is very apparent. The Neroly is represented by the adjacent grass- and oak-covered rounded hills to the south, which stand in sharp contrast to the steep chaparral-covered slope of the Briones to the north. 3.5 This is a rather spectacular overlook across Sycamore Canyon to the “hogback ridges” plunging down the western edge of Blackhawk Ridge into the canyon. Immediately to the left beside the road are corresponding beds forming Fossil Ridge . There are several beds with fossils exposed here, but the park does not allow “pull-outs” except in an emergency. You may want to proceed to the South Gate Entrance Station just ahead and get permission to park there briefly and walk back down to the overlook. These “hogbacks” represent the basal (oldest) beds of the Briones Formation. As you walk (drive) back to the entrance station you will be in an underlying siltstone unit, with pebbly siltstones and conglomerates. Less resistant to erosion, this interval of Miocene beds forms a characteristic grassy “saddle” between the overlying Briones, and the underlying Mid-Eocene “Domengine.” 3.65 South Entrance Station . After passing the entrance station, you will be entering the mid-Eocene “Domengine Formation.” The rocks exhibit a wide variety of erosion features. As we now travel northwest away from the entrance station, the deep valley to the north (right) is formed by the West Fork of Sycamore Creek. The rocky slope across the valley is Domengine as well. It is interesting to note that after passing the chaparral-covered Briones, we now find that the gray pine has become a prominent tree. They seem to thrive in the sandy soils of the Domengine and their presence has been used to help map the Domengine outcrops on the north side of the mountain in Black Diamond Mines Regional Park. 4.1 The rocks you soon see on the right are the upper most part of the "Boy Scout Rocks", a group of rocks popular with climbers. A short distant ahead on the left is the massive monolith called "Gibraltar Rock". 4.5 Rock City. There are many short trails for exploring this area that include the Wind Caves, Sentinel Rock and other fascinating erosion features. The Wind Caves at Rock City are not formed by wind, but in fact are formed by water percolating through the sand and dissolving the cement holding the sand grains together. Note the iron stained bands in the sandstone near the Wind Caves. They are known as Liesegang structures. These formed as a source of iron hydroxide diffused through the sandstone creating a beautiful banded appearance in the rock. The sandstone rocks here are part of the Domengine formation of Middle Eocene age, deposited down slope of the shelf edge in deep water. The sandstones form prominent ridges which rise well above the surrounding landscape and trend for several miles along the flank of the mountain. This area also offers parking access to the Trail Through Time . An Overview Panel is located near the restroom building. 4.6 After passing the ranger’s house on the right, you will be driving over rocks that are less sand and more shale, a significant change from the massive sandstones of Rock City. During the next half mile, you will notice the trees give way to more open grassland. 5.2 Curry Point . There is a pull-out here at Curry Point that provides a view of the distant Sierra on a clear day and the summit of Mount Diablo to the north. Rocks of the Franciscan Complex cap the mountain. Looking north, the nearby valley is formed in shale of upper Cretaceous age. The Cretaceous beds are separated from the Franciscan Complex by a major thrust fault. The fault trace on the surface is mostly covered by landslide deposits. Above the thrust fault is Franciscan mélange material and farther up is the hard resistant greenstone and chert forming the rocky crest of Mount Diablo’s main peak and North Peak. The protruding rock to the east of Mount Diablo summit is Devil’s Pulpit, a resistant chert outcrop. After leaving Curry Point, you will be driving west, parallel and just above the contact between Upper Cretaceous shale to the right and the younger early Eocene beds to the left. 5.8 Near this point, you will be crossing over the Cretaceous/Eocene contact. This contact is a major unconformity with a hiatus (an interval of time represented by the missing rocks) of about 25 million years where 15 million years of Upper Cretaceous rocks and the entire record of Paleocene history is missing. This unconformity marks the boundary between the Age of Dinosaurs and the Age of Mammals. 6.0 Here you turn to cross the open valley to the north. 6.1 Thrust Fault . After passing a sign that says “2000 Feet,” you will notice on your right a slight dip in the surface of the road bank with a sign that says “Authorized Vehicles Only” and a trail Interpretive Panel. Take the opportunity to park along side the road here. If you examine the road bank (facing east), to the left you will find blocks of Franciscan chert and greenstone. To the right down the road about 20 to 30 feet, these rock types are missing; instead you will see an exposure of brown shale in the road cut. These two rock types, Franciscan to the left and Upper Cretaceous to the right, are separated by a major thrust fault. Franciscan rocks have been thrust up to the southwest and over the younger Cretaceous shale. There is an interpretive panel here that describes the geology at this point. From this point to the Junction Office, you will be driving in Franciscan mélange, where large blocks of typical Franciscan rocks are exposed along the side of the road. The red-brown soils are characteristic of the iron-rich greenstone that makes up much of the Franciscan on the mountain. Red radiolarian chert, along with lesser amounts of shale and graywacke are also exposed. 6.8 Junction Office—End . Northgate Road - Walnut Creek Entrance 0.00 Set odometer to “zero” at the North Gate entrance kiosk . For the next 1.6 miles you will be traveling over Upper Cretaceous sedimentary rocks made up mostly of shale with some sandstone beds. The topography consists of low rounded hills cut by the Little Pine Creek running parallel to the road. Beds dip steeply to the southwest. 1.6 Park Boundary. Continue traveling on Upper Cretaceous rocks. The rocks at the top of the hills to the right are Eocene in age. The eastern branch of the Concord Fault follows the road in this valley. 1.9 As you turn left and then right, crossing a stream gully, you will notice gray-green rocks along the left side of the road cut just before you cross over the gully. The gray-green rock outcrop itself is a badly weathered exposure of serpentinite, forming the westernmost edge of the long serpentinite band that runs easterly across the mountain. The fault that separates the serpentinite from the Franciscan is probably expressed topographically by the east-trending gully at this point. The fault plane dips down to the north. The serpentinite is separated from the Upper Cretaceous beds (on which you have been traveling) by a major fault. As you cross the gully and round the next bend (again driving briefly on the Upper Cretaceous shale), you will notice a large rock outcrop ahead on the left side of the road. It is at this point you once again cross a major fault. Continue in the Franciscan Complex from this point on. The large imposing rock outcrop is greenstone, not serpentinite. As you continue to drive south, keep an eye out for the typical assemblage of rocks you find in the Franciscan Complex—greenstone (basalt), red radiolarian chert, graywacke, and shale along with a few blocks of dark blueschist. In this area, these varied rock types are enclosed in a mélange. 3.1 Camel Rock. As you approach 3 miles, watch on the left for Camel Rock—a rock outcrop that (with the help of a little imagination) resembles the outline of a single hump camel. After you pass the rock for about 100 feet, you will get the best view if you look back toward the area you have just traveled. To walk to the outcrop, best access is from Burma Road near where it crosses Northgate Road. Red Radiolarian Chert 3.4 Just past Camel Rock, you go over a rise of a hill and you will notice ranch buildings ahead. The prominent ridge across the valley to the west is made up of lower-Eocene-age sandstone and shale while the valley below on the west side of the Mount Diablo Thrust Fault is Upper Cretaceous. The Mount Diablo Thrust Fault itself runs along the slope about halfway between the road and the creek bed. The hills are relatively treeless, typical of an unstable soil such as a mélange. 4.6 As you round a bend at this point you will notice a pile of rocks ahead. This rock formation is called Turtle Rock . It is made of radiolarian chert and from this perspective doesn’t look much like a turtle. Better views later. As you pass the “Diablo Ranch” gate, you will be traveling on material formed by a large landslide . This material also encloses blocks of Franciscan rock types and looks a lot like mélange topography. It is often difficult to distinguish the two landforms from each other. 5.0 If you look down hill to the left, you will get a good view of Turtle Rock. 5.3 Here you may want to pull off the road to the right along an open grass area and walk the short distant to the large block of blueschist exposed here. In the past, stone was quarried from this area. This schist is common in the Franciscan mélange and is named for the noticeable blue color of the mineral glaucophane . Blueschist is largely altered basalt and reflects a history of hi-pressure/low- temperature metamorphism. On Mount Diablo it is about 165 million years old. You will continue traveling on landslidematerial containing large blocks of Franciscan rocks up several Blueschist | Roi Peers major switchbacks. Look back as you go and you will see that Turtle Rock is aptly named (shell to the south and head to the north). 6.25 By the time you reach the ranger’s house, you will be out of the landslide and back into Franciscan mélange topography. 6.6 Junction Office—End Summit Road - Junction Ranger Station to Summit 0.00 Set your odometer to “zero” when you turn up Summit Road at the Junction Ranger Station. The entire drive to the summit will be in the Franciscan Complex. Watch for the characteristic exposures of Franciscan type rocks including red charts , greenstone (basalt) , and a few outcrops of graywacke and blueschist . The soils are typically red-brown in color due to the high iron content of the parent rocks. Between here and near Toyon Picnic area the drive will be through Franciscan mélange . 0.5 As you round the curve (turning right) after passing the Rocky Point Picnic area , you will notice a dark blue-black boulder about 5 feet across protruding from the bank on the left side of the road ahead. This is one of the rather common blueschist found in the Franciscan. Blueschist is largely altered basalt and reflects a history of hi-pressure/low-temperature metamorphism . On Mount Diablo it is about 165 million years old (younger than the greenstone, but older than the graywacke). 1.15 To the left you will pass a prominent exposure of red radiolarian chert . If you pull off at the turnout, you will also be able to look out over the ridges of younger rocks to the south. As you look south and southwest, the valley below contains Cretaceous rocks bordered on the north by a thrust fault that separates it from the Franciscan Complex and on the south by younger Eocene age rocks that include the yellow-tan sandstone exposed around Rock City and Castle Rocks. The more distant row of ridges (Fossil Ridge, Blackhawk Ridge, and Oyster Point) are Miocene in age and are quite fossiliferous. If you look to the north, you will see the rugged chert-greenstone capped summit of Mount Diablo. 1.5 At about 1.5 miles, you will leave the mélange and the chert and greenstone outcrops become more frequent. 1.9 On the right side of the road and continuing for another 0.2 miles, is a major (and typical) outcrop of sheared and broken greenstone (basalt). 2.3 Pull out on left at Juniper Camp Ground . Good views to the west. You will be looking out over the San Ramon Valley and the towns of Danville, Alamo and Walnut Creek (left to right). The Calaveras Fault runs down a portion of this valley. The ridge on the far side of the valley is Las Trampas Ridge and is made up of Miocene age rocks similar to the Miocene age rocks on Mount Diablo including highly fossiliferous sandstone beds. 3.2 Another good exposure of greenstone , highly sheared, with slickensides visible. 3.55 As you make a sharp turn to the left (“Devils Elbow”), you may want to pull off here to view a moonscape of more chert and greenstone rocks toward the north, capped by the prominent chert outcrop known as “Devils Pulpit”. These rocks are resistant to erosion and are responsible for the rugged topography. Back on the road, the red rock immediately on the right is thin-bedded radiolarian chert with interbeds of reddish shale. Continue to the summit. 4.5 Summit parking lot . The summit museum has an excellent geology display. A short walk along the Mary Bowerman Interpretive Trail is also recommended. This is a quarter-mile walk along the northside of the mountain to an overlook platform. The trail is accessed from the Lower Summit Parking Lot. There is an informative Geology Interpretive Panel at the end of this short walk to the platform that describes the geological setting of the mountain’s northside. This short walk will also provide an opportunity to inspect greenstone, graywacke, red chert, and a small amount of shale up close. The quarry you see to the north is producing diabase (part of the Mount Diablo Ophiolite) for crushed rock used in the construction of roadbeds. Reproduced from Geology of Mount Diablo by Roi Peers

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