More than 1,000 runners hit the trails on Mount Diablo on Saturday morning, participating in one of four different races on the state park's trails.
Entrants in the 5k, 10k and half marathon races all started and finished at Castle Rock Park on the mountain's Walnut Creek side.
The hearty participants in the 50k (31 mile) race began their trek at Round Valley on the mountain's eastern slopes. They finished at Castle Rock Park.
The event raised money for Save Mount Diablo. Officials at the organization say the races also help raise awareness of the mountain and its scenic beauty. More information on the race, including results, can be found on the group's website.
Saturday's race was held in sunny, 80-degree weather. It was in contrast to last April's event, where it was rainy and muddy.
The racers ranged from the elite runners who sped through the shorter races at 7-minute per mile pace to participants who walked the entire distance.
Elementary school age children jogged along with people old enough to collect Social Security.
The organization hosts another set of trail races in November.