The animal population I am most frequently asked about is that of the mountain lion, also called the puma or cougar. There are twenty-seven different subspecies. The local variety is one of the largest subspecies, but it has become extinct in may of the areas where it once thrived. It would not be entirely accurate to say that there is a mountain lion population on Mount Diablo. Lions have been known to range over 20 miles in one night. They use Mount Diablo as part of their range.

No other animal presents a stronger case for the importance of wildlife corridors, such as the one connecting Mount Diablo with Morgan Territory park, and with Black Diamond Mines Regional Park. Over the years, there have been many mountain lion sightings. Here's a glimpse of a few recent ones: a very large, dark-colored mountain lion was seen on Mount Diablo in the Pine Canyon area; a mountain lion and cub tracks appeared around my photography blind while I slept one night in 1989 on Mount Diablo, and; a mountain lion and cub (I believe the same pair) were spotted a few weeks later near Danville. Still another sighting of an adolescent occurred on the road near Juniper campground in 1990. All three of these young lion sightings were probably the same lion. I also got a fleeting glimpse of an adult last year in the Morgan Territory area. Based on these sightings and others, I believe a handful of mountain lions use Mount Diablo as part of their range. While it may be true that Mount Diablo is the most important part of their range, without corridors to other protected lands, they will probably not survive in the area.

Download Common Mammal Tracks of Mount Diablo (pdf)