I think you and I are talking about the same one. Heading down 29 towards 485 you'd make a right onto an access road (Morningstar rd?) briefly before jutting off to your right and down into the trail. You would immediately see this mound upon entering the trail:
What is the other spot like? Where do you access it?
Another spot I've tried couple times but is quite risky is the one right at the corner of John Kirk and Mallard Creek Church. You have to make your timing right so no really sees you turn off the road.