The Black Rock Lake Trail leaves its junction with #10W36 and heads northwest through Pettijohn Basin and contours through open stands of pine and fir timber and small meadows to Black Rock Lake. There is good water along the first half of the trail.
Directions from Harrison Gulch Ranger Station: Drive 7 miles west of Harrison Gulch on Highway 36 to the Wildwood Mad River Road (#30). Turn south and continue approximately 10 miles to Pine Root Saddle. At the saddle turn east on the Middle crest Road (29N35) and continue approximately 11 miles. At Stuart Gap junction turn right on 28N62 and continue another 2 miles to the trailhead. From the Stuart Gap Trailhead take trail #10W36 approximately 1 1/4 miles to Pettijohn Basin and junction with #10W34 (Black Rock Lake Trail.