Use this road to access the fabulous Oyster Point Trail
on the eastern side of Mt. Diablo State Park.
Starting about 1 mile from Curry Point on Knobcone Point Road
take the right turn. The road descends quickly on a loose, rocky fire road surface until it reaches the creek at the bottom of the canyon. At the creek, take a left to stay on Black Hawk Ridge Road and ascend sharply for about a mile. You'll reach a 4-way intersection in a clearing with great ridge views.
The Oyster Point Trail
is the small non-descript singletrack that you would go on if you went straight through the intersection.
This description stops here but Black Hawk Ridge Road actually continues to the right.