Black Diamond Mines Regional Preserve

Mountain bike the moderate Stewartville and Ridge Trail Loop for 8.3 miles of challenging climbs, fast descents, and panoramic views of Moun

The Nortonville and Black Diamond Trail Loop offers a rugged mountain biking adventure through varied terrain, from grassy valleys to California oak woodlands. You'll encounter unpaved fire roads and some technical singletrack, with panoramic views over the Delta and Suisun Bay from higher points. The landscape shifts from green and idyllic in spring to more arid in summer, always providing a dynamic backdrop to your ride. This route is a great choice if you enjoy challenging climbs and historical exploration.

Planning your visit to the Black Diamond Mines Regional Preserve means being ready for some significant effort. This moderate 8.1-mile (13.0 km) loop features 1613 feet (491 metres) of elevation gain, typically taking around 1 hour and 33 minutes to complete. Parking is available at the preserve's entrance, but an entrance fee might be required. Be mindful of seasonal conditions; winter rains can create challenging 'death mud' sections, so spring or drier seasons are often preferred.

What truly sets this trail apart is its rich historical context, offering bike-based exploration of the region's mining past. You'll pass remnants like the Rose Hill Cemetery, the Black Diamond Shaft, and the unusual Jim's Place cave. The Nortonville town site also provides excellent views during descents. This blend of natural beauty and historical intrigue makes the Nortonville Black Diamond Trail Loop a unique mountain biking experience in Contra Costa County.

An easy 5.3-mile mountain biking loop in Black Diamond Mines Regional Preserve, offering historical sites and panoramic views.