"The trail is made up of two single track loops that form a figure eight. The direction of the trail is clock wise, so at the trail head go left. The two loops are Sister Grove Loop and the Lake Loop. At the junction of the two loops is a gate. When you get to the gate, always take a left.
It is beginner to intermidiate level trail. It is a rolling trail that winds it ways through open fields and woods. It has some good climbs on the Lake Loop and some fast fun down hills on the Sister Grove Loop. It has one tight twisty rooty wooded section near the end of the Sister Grove Loop that is challenging. " - From DORBA homepage
Driving Directions: From McKinney, go East on US Hwy 380 past Princeton to County Road 559. Take a left on CR 559 and head North. Merge left onto CR 561 to CR 562. Take a left on CR 562. Sister Grove Park will be on your left hand side.
http://www.singletracks.com/item.php?c=1&i=2253