The best MTB trails in Antioch Dunes National Wildlife Refuge

This barred tunnel was once a bustling entrance to the Star Mine, one of the most active coal mines in the area, providing a livelihood for many families. The rusted bars that now block the entrance are a stark reminder of the mine's past glory and the hard work that went into extracting coal from deep beneath the earth's surface.

This trail is a great alternate route from Ridge Trail to Stewartville Trail, with stunning views from the top of the hill. Plenty of cows call this area home and are not shy about the boundaries of the path, making it muddy and uneven if you visit after wet weather. It connects with the North Portal Trail, giving endless options to explore more riding trails in this beautiful preserve.

This steep portion of the trail provides a few switchbacks to ease the grade before reaching the Ridge Trail. There is a rest bench at the junction which is an ideal place to stop and catch your breath while you and take in the views of the incredible scenery.

The Stewartville Trail starts just south of the parking lot and runs through the preserve from east to west, linking the former Somersville and Stewartville mining towns. The route gradually climbs through a small, beautiful valley and can be ridden in either direction, but clockwise is recommended for the best ride. The trail offers excellent views in all directions, with Rose Hill Cemetery visible in the distance while looking west, Sand Creek Valley to the east, and Mount Diablo to the south.

This preserve is a treasure trove of history, home to the remnants of three mining towns, including former coal and sand mines. The park features include an underground visitor center, guided tours of a former sand mine, and 60 miles (97 km) of trails to explore that crisscross the rolling foothill terrain. The trails offer stunning views of the surrounding landscape, which is a mix of grassland, California oak woodland, California mixed evergreen forest, and chaparral, making it a nature lover's paradise.

The Rose Hill Cemetery is a site of historical significance that commemorates the memories of the miners and their families who once resided in this area. It pays tribute to the lives of numerous individuals, including children who passed away during epidemics, women who lost their lives during childbirth, and men who died in tragic mining accidents. It's a good place to stop and catch your breath before continuing on to the next incline.

This once 150-foot-deep air shaft was put in place to ventilate a coal mine to keep it free from dangerous gasses. There is a short tunnel to access the interior and get a closer look. On the excavation sides, there is still evidence of marks left by the picks from miners.

The origin of this unusual little underground dwelling is unknown. You can see a round stovepipe hole, a square skylight, and a shelf opening from the interior.