Went to Draper yesterday 8/19. Yes, it is legal to drive there. There are off road trails that completely circle the lake. The best areas that I have found so far are on the east side of the Lake adjacent to SE 89th street. Anything you want is there, rock (BIG rock in some places), sand, STEEP hills, and mud, if it will ever rain here. Many of the locals go here, some built and some not, as the trails range in difficulty from mild to wild. I was able to get a wheel of my '86 K5 off the ground a few times because of some extreme angles. There really are some excellent trails here, and you are no more than 20-25 minutes from OKC at any location around the lake. Anyone interested in a tour, leave a post. God has a hard on for Marines, because we keep Heaven chock full of fresh souls!