To get to the trailhead, drive along the Bollinger Canyon Road westbound until the end (about 10 minutes driving from the Crow Canyon Road intersection). About a half mile after passing the gate, the staging area will be on the left where you can park your car and use the bathroom. (If you arrive outside of open-gate hours, you may find the park gate is closed, but don't panic. You can park at the left side of the unpaved parking area and head through a small gate to the right. After about 500 ft, make a left and go up the hill gradually.)
The trailhead is located on the left side of the picnic area, and the first mile is along the foothills of Rocky Ridge toward the east. At about 0.3 miles, you'll reach a horse camp. Follow the Elderberry Trail sign and turn right to start climbing. As you climb, look east for a pleasant canyon view.
After about 2 miles, you'll arrive at the junction of Elderberry Trail and the Rocky Ridge View Trail
. Enjoy a quick rest on the chair donated by a hiker's friend, while enjoying the panoramic view of Mt. Diablo, Tri-Valley, and San Mateo Bridge. You can continue to hike toward the east along the ridgeline until you reach the park boundary, or you can just return the way you came down the hill all the way back to the parking lot. This can be an easy, relaxing 4-miler or 5-miler if you add the ridgeline extension to the boundary.