The 18 mile drive to the park from Pioche is along paved Hwy 322, initially across an wide plain, then over a low ridge and down towards the shallow canyon of Meadow Valley Wash, here known as Eagle Valley
. Downstream, this leads to similarly small preserve with a reservoir (Echo Canyon State Park) then, after passing close to Cathedral Gorge
, enters a longer canyon containing another state park, Kershaw-Ryan
. The main road however goes upstream, where the valley becomes briefly wide but soon narrows, and the paved section of the route ends beside the dam forming Eagle Valley Reservoir, at the entrance to Spring Valley State Park. Near here is the day-use area, the boat launch ramp and pier, and Horsethief Gulch Campground, which has 37 sites, and can accommodate RVs up to 35 feet in length. An unpaved road proceeds along the north shore of the reservoir and the edge of the marshy grassland beyond, past two stone buildings to the park headquarters, contained within another historic structure, Millet Ranch
one of several former settlements in the valley; the first was established here by Mormon pioneers in 1864. The smaller (seven site) and more primitive Ranch Campground is just beyond, after which the road continues northwards, exits the park and leads through increasingly remote terrain.
Stone Cabin Trail
The one hiking path in the park is the 1.3 mile Stone Cabin Trail
, which starts in the south at a pull-out along the road and ends in the north at the Ranch Campground. A 2.2 mile loop can be made by walking back along the road. The southern trailhead is at Stone Cabin
, one of the three largest ranch buildings in the park; a well-preserved and partly restored structure enclosed by a small, fenced, tree-lined garden, beside which are an old pioneer wagon and several pieces of agricultural machinery. The path starts off northwest across a wooded flat, before climbing about 300 feet up more open slopes where the white or pinkish volcanic rocks are prominently exposed, then descends to the upper end of a small valley with more outcrops, followed by a longer traverse of grassy, sparsely wooded slopes. It drops down to a wider ravine, rises once more and enters the short, cliff-lined canyon that contains the Ranch Campground. The last part of the route has good views eastwards across the main valley, here centered on a distinctive, isolated white outcrop surrounded by grassland, known as George Washington Rock.