The Ashuwillticook Rail Trail is a great bet for a flat, longer distance, all off-road run in the Berkshires. The paved multi-use trail runs for 13.5 miles between Adams and Lanesborough. Ashuwillticook is named after the Native name of the South branch of the Hoosic River, which translates roughly to “the pleasant river between the hills.” The landscape is a combination of open and wooded, with some great views of the Hoosac Mountains, Hoosic River, Cheshire Reservoir, and the wetlands which wind between them. There are numerous access points and parking areas. This would be a great route in autumn!
We’ve mapped the full trail, starting in Adams. The section near Adams goes through the center of town, and features views of some former factories of this once significant industrial town. One of the nicest sections is the ~2 miles along the Cheshire Reservoir, toward the southern end. There are great views of the water & mountains.