Trail Manager: Empire Mine State Historic Park | Contact (530) 273-8522
Length: 4 miles, varies with route chosen
Altitude Change: 290′ Maximum
Trail Surface: Natural Earth
Facilities: One picnic table near the top of Inner Loop. No other facilities.
Rules: Trails open from dawn to dusk; stay on marked trails; no motor vehicles; no camping; dogs must be on leash; all natural and historic features are protected. Stay out of closed areas. Caution: poison oak, ticks, rattlesnakes
Trailheads: Of the three trail areas in Empire Mine State Historic Park, the Osborne Hill Trail Area is the only one that does not have a trailhead with parking immediately adjoining the trail system. Official access to the Osborne Hill trails is from the following two trailheads, located along East Empire Street:
Penn Gate Trailhead: From Highway 49 in Grass Valley go 1/2 mile east on Empire Street and enter the trailhead parking area on your right. There is a large supplemental parking area for horse trailers behind the car parking lot. To reach the Osborne Hill trails, follow the popular Hardrock Trail south from the Penn Gate (N39.20940 W121.05717) about a mile to either the Osborne Loop Crosscut Trail (N39.20018 W121.05336) or the Osborne Loop Trail (N39.20173 W121.04544), both of which will be on your right.
Visitor Center Trailhead: From Highway 49 in Grass Valley go east on Empire Street 1.25 miles to the main visitor parking lot at Empire Mine State Historic Park. At the far southeast end of the main parking lot (to your left as you face the mine yard) you will find a metal gate and wayside exhibit that form the eastern trailhead for the Hardrock Trail (N39.20663 W121.04493). To reach the Osborne Hill trails, follow the Hardrock Trail south about 0.4 mile. Just after you cross Little Wolf Creek take the Osborne Loop Trail (N39.20173 W121.04544) uphill and south from the Hardrock Trail.
Trail Facts: The Osborne Hill Trail area makes up the southern arm of Empire Mine State Historic Park. The excellent trail system here has many loops, making for boundless riding or hiking options through deep woods and some open areas. There are remnants of several mines and tailings can be found along the trail. The Empire Mine State Park area as you see it today contained a complex of mines that were developed to get at gold-bearing rock veins below the surface. There were at least five mines in the Osborne Hill area, with varying levels of mining activity from the 1850’s into the 1930’s. Most easily visible here are impressive remains of the Prescott Hill Mine which, combined with several neighboring mine properties in 1903, had a shaft down to 1,750′ and was active into the early 1930’s.