Singletrack starts from Minor Bridge, couple of uphills to start, then some nice downhills. Look for turn offs to the left, they offer a great couple of miles of singletrack. After the single track it is about 2 miles on smooth abandoned railroad tracks to Route 67 and the main parking lot.
Starts just above the Roxbury Falls, near 50 Minor Bridge Road. Park at the falls. Alternate entrance near Ed Orzaks Farm next to Route 67, if you enter through this way you will have to bike a mike or two on a 4x4 type trail to the singletrack.
http://www.singletracks.com/item.php?c=1&i=6624