“Singletrack access past Stonegate neighborhood into Mt. Diablo State Park.
— Mike Anciaux
The trail starts near the beginning of Serafix Rd and parallels Serafix Rd until it turns into a singletrack that leads to Hanging Valley Trail
and Mt. Diablo State Park. When descending, the singletrack is a flowy and fast egress from the park (but it has limited sight lines, so watch for hikers).