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Empire Mine State Historic Park

Hardrock, Osborn Hill Trails

2 to 3 miles round trip

Empire Mine, one of California’s richest, produced more than six million ounces of gold during its 100 years of operation. The gold mine, along with 784 acres of gold country, is preserved in Empire Mine State Historic Park.

Shortly after the great gold rush of 1849, logger George Roberts discovered an outcropping of gold-bearing quartz about where today’s visitors park their cars. Miners swarmed these hills to lay claim to the riches below. Trouble was, the gold was way below the surface, which pretty well thwarted most of the low-tech, low-budget prospectors. The miners dug 20- to 40-foot “coyote holes,” tunneled and blasted, only to see their efforts fall victim to cave-ins or floods.

Around 1851, George Roberts and his fellow gold-seekers sold their claims to a consortium that consolidated them and dubbed the operation the Empire Mine. San Francisco businessman William Bourn and his son William Jr. took over in 1870 and, after investing more money and digging deeper than many thought possible, eventually turned a profit in the 1880s and beyond.

Much of the Empire’s success can be attributed to the experienced hard-rock miners from Cornwall, England who came here. By some accounts, the 1890 population of Grass Valley was 85 percent Cornish.

Park visitors can get a look at the main mine shaft from an observation platform. At the visitor center are interpretive exhibits and gold samples displayed in an open vault.

The advantages of owning a gold mine are evident when one Empire Cottage, an English manor-style home designed by famed San Francisco architect Willis Polk for William Bourn, Jr. in 1898. Quite a “cottage!”

Join one of the park’s scheduled tours of the Empire Cottage and/or Empire Mine. Or take a 16-stop walking tour on your own past structures, building foundations and mining machinery.

After your history walk, hit the trail. The park has ten miles of pathways—above ground that is. Below the earth is honeycombed with some 367 miles of tunnels, some nearly a mile deep.

Across the highway from the visitor center is the Union Hill section of the park. This part of the park is wooded (sugar pine, ponderosa pine, incense cedar and Douglas fir), along with some oaks and big leaf maple. A few fruit trees—apple, pear, cherry—are reminders of early settlers in the area.

Three trails, one to three miles long, explore Union Hill. Along Pipeline Trail are remains of a waterpipe that carried water from a reservoir to the
north and generated power to operate mining machinery. Indian Ridge Trail is a historic pathway used by the Nisenan tribe of Maidu. Union Hill Trail skirts the fringe of the fast-growing community of Grass Valley.

Two mile long Hardrock Trail is a 20-stop interpretive trail that visits mines, machinery, a mule corral, a stamp mill and much more. Pick up the park’s “Walking Trails of Empire Mine” brochure to get all the details of the complexities of hard-rock mining. Osborn Hill Loop Trail, a mile-long side trail splitting off from Hardrock Trail, ascends to a couple more mine sites and offers a great view of the Sacramento Valley.

Directions to trailhead: Empire Mine State Historic Park is located in Grass Valley, just east of Highway 49 on East Empire Street. Follow the signs from the highway to the park.

© 2012 The Trailmaster, Inc.
From John McKinney’s
Day Hiker’s Guide to California’s State Parks
Trail descriptions and maps have been reproduced with the permission of the author.  To learn more about The Trailmaster and other related publications please visit their website at