1.3 hr
From the oak savanna near the visitor center, the Mitchell Rock Trail heads south and then west. Pretty soon, you'll be on Mitchell Rock, which has a fine view of Mitchell Creek Canyon. Keep climbing, zigzagging through grasslands, oaks, and chaparral, until you reach Twin Peaks, another rocky outcrop with views of Mount Diablo and its surrounding peaks. From there, the trail heads south to end at the junction with Eagle Peak Trail.
Mount Diablo and Eagle Peak seen from Mitchell Rock