Forest Route 21s03 is a hiking, biking, and horse trail in Monterey County, California. It is within Ventana Wilderness and Los Padres National Forest. It is 3.3 miles long and begins at 1,580 feet altitude. Traveling the entire trail is 6.7 miles with a total elevation gain of 1,103 feet. The Avila Ranch residential can be seen along the trail.