Black Diamond Mines is one of East Bay Regional Park District’s larger parks. It has 2 entrances in Antioch, along with an additional western entrance in Clayton. The park features miles of hiking, mountain biking, and equestrian trails.
The most popular entrance is from the Somersville Road entrance, parking fees are a few dollars on the weekends and free on the weekdays. There is a free parking lot on Fredrickson Lane near Contra Loma Regional Park. From the trailhead nestled in a valley, the many miles of trails only go up from there. The hikes are relatively easy and non-technical, but be advised that there are a good number of hills. There is little tree cover for most of the park, so make sure to bring a hat and sunscreen.
The park’s namesake comes from the original coal and sand mines that prospered the former towns of Somersville, Nortonville, Stewartville, and West Hartley. The towns are remembered by their names being dedicated to many trails and mines, along with the arterial Somersville Road in Antioch. The towns, now nonexistent, were home to up to a thousand mine workers and other supporting industries. The only remaining structures of the towns are the Rose Hill Cemetery, and the mines themselves. The cemetery can be hiked to by starting at the Somersville trailhead and walking up the hill on the Nortonville Trail. The underground mines are opened to the public but only on a guided tour, which can be reserved on the park’s website.
Nature lovers will be taken away by the hawks that can soar along the hillsides and the variety of tree species you can find here. Grey pines can be found in the southeast on the Star Mine Trail—a favorite trail of mine because it’s cool and shaded. Just watch your head for the Grey Pine’s heavy coconut sized pinecones, which can weigh several pounds. Near the main entrance by the Stewartville Trail, you’ll see Black Locust trees and elsewhere in the park, you can find Oaks on the ridges and Manzanita in the chaparral areas.
March through May is the best time to visit the park. The wildflowers are blooming, it’s relatively cool, and recent rains keep the hills green. Due to COVID-19, some parking lots are closed to reduce overcrowding and the visitor’s centers, restrooms, and mines are also closed. However, all the trails are open, though I encourage you to check here for park updates before planning your next trip. Also, please note that the entirety of the park will be closed on Easter Weekend to encourage social distancing.
Being a native resident of Antioch, Black Diamond Mines is the park that I grew up in. It’s essentially the open-space park where I learned to hike and grew an appreciation for the natural world around me. The wonders of Black Diamond Mines introduced me to nature and took me on a path to hiking, which led to backpacking and eventually going to college to major in environmental science. The rest is history, and I owe much of it to this park.