Head left from the parking lot down the red-blazed trail. This trail continues left or branches off right (the beginner trail) continue left down a fairly fast flow section with a few obstacles. The trails winds around as you descend through the woods.
You'll approach a small rock garden, followed by a "caution" sign indicating the first of three creek crossings. It's a fairly technical descent followed by a fairly steep (but short) rocky incline. At the top of the hill, the path breaks off to the left (expert trail, clearly marked) or continues to the right meeting up with the intermediate trail (clearly marked).
The trail continues through a fairly flat section surrounded by tall grass until you reach the second creek crossing followed by the most technical climb of the trail. After the climb the trail continues winding through the woods following the lay of the land up and down some fairly easy hills until you reach to third creek crossing.
From this crossing, the trail continues with the last part a fun, flow-y roller coaster-like section with a few technical area sprinkled in. The trail finally joins the beginner trail until it reaches the parking lot at the end after a decent climb back to the gravel parking lot.
note: Officially the trail starts off on the east side of the parking lot, and should be ridden in that direction, but riding it in "reverse" offers its own challenges and rewards.
Follow this link for the original map of the keystone lake mountain bike trails, on the Oklahoma Earth Bike Fellowship. okearthbike.com/trails/trai…