At just under 6,000 feet, this is a good late-spring run when everything higher is buried in snow. On Forest Rte 26, about nine miles west of the turnoff to Castle Lake, a turnoff leads immediately to a bridge across the South Fork of the Sacramento River. This trail starts from a parking area about 100 yards southeast of the bridge.
Most of the route is labeled as a 4-wheel drive road. Only the last half mile is a singletrack trail. The first 1.5 miles is an easy run through the forest with the sounds of the Sacramento River and Soapstone creek below. Even without 4-wheel drive, some high clearance vehicles will be able to drive this part. At the 1.5 mile junction, the larger road switches back and begins a moderately steep climb.
It is still a pleasant run through the trees, and we pass a stream with good water. At 2.5 miles, we reach a couple of switchbacks, and the road becomes much steeper. At 2.9 miles, there is a parking area.The next 0.35 miles is probably too steep and difficult for many 4-wheel drive vehicles; however, I saw a very high-clearance truck at the top. The last 1/2 mile to the lake is a singletract trail with a moderate climb and few trees.
Gray Rock Lake sits in a shallow basin below rocky cliffs. There are good campsites under the trees. The inlet stream is difficult to reach, so you'll probably need to pump water directly from the lake. The trail to Upper Gray Rock Lake
and Timber Lake leaves from the east side of the lake.
Remarkably, I did not see a single flower above 3,000 feet anywhere along or above the South Fork of the Sacramento River. This is in great contrast to the profusion of flowers in nearby parks such as Marble Mountain, the Russian Wilderness, or Mt. Shasta.