West of Concord in Merrimack County, there is an extensive dirt bike trail system around Henniker Trails. In the past, these trails were maintained by the Contoocook Valley ATV Club, which disbanded prior to summer 2005. Many of these dirt bike trails and bridge network are maintained by the Henniker Trail Travelers club and the Army Corps of Engineers. Portions of the trail system are closing due to bridge loss and change in private property. Be very careful to ride only on approved routes (which can be difficult to determine). You really need to contact the Henniker Trail Travelers club to find out the latest status of OHRV usage on these trails.
Overall, Henniker Trails is the 6th most popular dirt bike trail of all 18 dirt biking rides in New Hampshire.