National Forest Development Road 401 is a hiking, biking, and horse trail in White Pine County, Nevada. It is within Humboldt-Toiyabe National Forest. It is 24.5 miles long and begins at 6,798 feet altitude. Traveling the entire trail is 4.0 miles with a total elevation gain of 263 feet. The Eberhardt Post Office (historical) (elevation 7,215 feet) and Hamilton Post Office (historical) (elevation 8,058 feet) post offices and the California Spring Forest Service Facility (elevation 8,100 feet) public building can be seen along the trail.