Runners follow an out-and-back course for the half marathon that starts and finishes in Walnut Creek’s Civic Park. From there, the course makes a clockwise loop along Oak Road, Treat Boulevard and Cowell Road before turning right onto Ygnacio Valley Road, which they’ll follow as it heads southwest all the way into Heather Farm Park. The race’s biggest hills occur around the half-way point along Cowell Road; after that, the course heads back downhill and flattens out most of the way in to the finish line.
(MORE: Walnut Creek Half Marathon event details)