Diablo Trail Run

Diablo Trail Run takes place on September 6, 2026 at Diablo State Park (Mitchell Canyon Trailhead) in Clayton, CA. The event offers multiple measured trail distances and a separate kids run. - **4 Mile** - **10 Mile** - **Half Marathon** - **Marathon** - **50K** - **Kid's Run: 50 yard dash, age six and younger, free** Mount Diablo provides views of the San Francisco Bay Area and surrounding valleys. The **4 mile** course is described as relatively flat and fast within Mitchell Canyon.

The longer routes ascend the mountain and include more single track and scenic sections. Course markings use colored ribbon about every 200 yards and polka-dot flagging to indicate turns. Blue ribbons mark wrong directions. Elevation gain and surface vary by distance, from about 400 feet for the 4 mile course to about 8,000 feet for the 50K.

Surfaces include dirt road and single track, with small asphalt sections on some distances. Fully stocked aid stations are placed every 3 to 5 miles offering fruit, salty snacks, candy, water, and an electrolyte drink; runners are advised to carry at least 20 ounces of water between stations. The event is cupless; participants are asked to bring their own fluid container and limited reusable cups are available for purchase. Additional notes: check-in occurs at the Mitchell Canyon Trailhead on race day, parking is $6 per vehicle, no dogs are allowed on course, and headphones are permitted only on dirt road sections. Visit the organization's website for the most recent information.