Lake Somerville State Park has a trail connecting the Nails Creek and Birch Creek Units (map) . Both Nails and Birch Creek Units have designated equestrian trails and campsites; however Nails Creek Unit has recently become a day use only park and campsites may not be used at this time.

The main riding trail is 13.5 miles long, with branching loop trails. The trail length is 21.6 miles. Users must provide their own horses. The terrain is hilly and rocky at the trail access points, but flat and grassy in between. All paths are multi-use and open to hikers, cyclists, and horse riders. There are self-composting toilets and shade shelters spaced along the trail. Non-potable water sources, as well as creeks and streams, are available for horses, but campers must carry in their own drinking water. There are five (5) group-camping areas along the trail with benches and fire rings. Individual campsites are located at either end of the main trail (Nails Creek Unit has 10, and Birch Creek Unit has 20). The individual campsites have fire rings, picnic tables, grills, and nearby drinking water. Nails Creek Unit has a horse pen and hitching posts. Birch Creek Unit has hitching posts only. Please contact either the Birch or Nails Creek Units to check for trail closures and campsite availability.