Reservoir Access Road is a hiking, biking, and horse trail in Middlesex County, Massachusetts. It is within Middlesex Fells Reservoir and Middlesex Fells Reservation. It is 1.4 miles long and begins at 227 feet altitude. Traveling the entire trail is 2.7 miles with a total elevation gain of 264 feet. Cairn Hill (elevation 302 feet) and the Middlesex Fells Reservoir can be seen along the trail. Near the end of the trail are wetlands, a wetland, a wetland, and a wetland.