Old Big Oak Flat Road Trail is a hiking trail in Mariposa County, California. It is within Yosemite National Park. It is 3.7 miles long and begins at 4,856 feet altitude. Traveling the entire trail is 7.6 miles with a total elevation gain of 2,570 feet. The Old Big Oak Flat Road Trailhead Parking Lot parking is near the trailhead.