Cross Fells Trail is a hiking trail in Middlesex County, Massachusetts. It is within Middlesex Fells Reservation. It is 1.4 miles long and begins at 158 feet altitude. Traveling the entire trail is 1.1 miles with a total elevation gain of 331 feet. Cairn Hill (elevation 302 feet) can be seen along the trail. There are also parking and a stone along the trail. The trail ends near Hemlock Pool and another wetland.