At 3,849 feet, Mount Diablo is one of the tallest peaks in the Bay Area, standing proudly above its East Bay surroundings. The isolated, pyramid-shaped peak is home to Mount Diablo State Park, which preserves over 20,000 acres of ridges, oak savanna hillsides, and numerous watersheds. The centerpiece of the park, Mount Diablo’s summit, offers spectacular views of the Bay Area and beyond; on clear days, views of the snow-capped Sierra Nevada Mountains can be seen from the summit’s observation deck and tower building.
Recreational options abound within the park's borders. Popular with cyclists, Mount Diablo typically hosts one of the Amgen Tour of California cycling stages that occur each year in May. On any given day you’ll find cyclists powering up Diablo’s South Gate Road toward the summit. In addition to road cycling, fire roads and singletrack trails criss-cross Diablo’s slopes and offer hiking and mountain biking options. Mountain bikes are permitted on park fire roads and on some, but not all, singletracks. Check with the park for the latest trail status. The Summit Trail, which traverses Mount Diablo’s south-facing slopes, is open to both hiking and mountain biking. The Fire Interpretive Trail is a popular hiking-only trail with expansive views that is partially ADA accessible. It contours around and below the summit, exploring a burn and the natural recovery cycle from a fire in the late 1970s. The Great Loop Trail, also encircling Mount Diablo, is another popular route. The park is also known for rock climbing and hang gliding or paragliding launch sites.
The park is home to three main campgrounds and smaller group camps. The two largest campgrounds, Live Oak Campground and Juniper Campground, are set among a shaded coastal live oak grove near Rock City and higher up the mountain boasting views of Diablo Valley, respectively.
Park ecology is a mix of open oak savannah grasslands on the lower slopes and Manzanita and chaparral vegetation higher up. During late winter and spring, when the spring flowers bloom among a sea of vibrant green grass, Mount Diablo is an impressive site. There is also plenty of poison oak; be on the lookout while hiking around. Wildlife include deer, coyote, squirrels, fox, bobcat and mountain lion, bald eagles, golden eagles, and diversity of other bird species. Ticks are also common in spring in the open grasslands.
Mount Diablo’s rotunda summit building holds a visitor center and an historic beacon tower that assisted aviators with navigation in the early 20th century. The summit was also an important survey point in California. The expansiveness of Mount Diablo is easily appreciated from the summit view, where the mountain’s flanks flow outward beyond sub-peaks in all directions.
Dogs are permitted in the park in developed areas only, and they must remain on a 6-foot leash. Multiple parking areas are spread throughout the park at various points of interest, trailheads, and campgrounds. There are two access roads and entrance stations, North Gate Road and South Gate Road, and the latter is more heavily used. Both roads converge at Junction Ranger Station and continue up Summit Road to Mount Diablo's summit.