Union Reservoir is set in a granite basin with expansive mountain views. The reservoir has lots of small islands and is kept mostly full. The campground is adjacent to the reservoir, nestled in red fir and lodgepole pine forest.
From Highway 4, turn onto Spicer Reservoir Road (paved) and go 8 miles. Turn left onto 7N75; from there the roads are gravel. Continue .7 miles to a T-intersection. Turn right and continue one mile. Spicer Reservoir Road is 27 miles east of the Calaveras Ranger Station in Hathaway Pines, California.