Runners head onto the out-and-back loop course for the half marathon near the park entrance just off Bear Creek Road, and into the rolling grasslands and tree-shaded canyons of Briones Regional Park, which lies just south of Martinez. From there, the course takes those running the half marathon along a number of challenging uphill and downhill stretches, with some sections climbing nearly 900 feet over the course of a couple of miles during the race.
(MORE: Bear Creek Trail Half Marathon event details)