State parks in New Hampshire officially open on May 23. There is plenty of mud in the spring. There is no camping in the park. Be prepared to change riding techniques when switching from smoother paths to more rugged trails with loose rock and obstructions. In autumn, obstructions can be hidden by leaves.
Mosquitoes can appear in late spring and summer.
Check with a ranger to find out when hunting season begins in late fall. Trail maps are available at trailheads. In Chesterfield, between the town hall and school, turn left onto Old Chesterfield Road and follow brown signs for Pisgah State Park. After two-tenths of a mile turn right onto Horseshoe Road. After another 1.6 miles you'll reach a parking lot with information and maps.