Carnigie is all OHV. Its not a bad place to ride. Trails and singletrack aren't the big things there...Roads and hills..that's what they've got.
Not a place to ride in the rain though... The clay in the ground out there was used for bricks for years...and it will stick so hard to your tires that you can't move.
About 2 hours south of the place pictured is a place called Clear Creek OHV. it is 100x larger and has endless miles of single track trails, fire road, hillclimb, etc etc. same type of terrain and even up into some pine forest.
carnige, after you have ridden it for a while gets old... but it is only 45 min from my house... and is great for a late afternoon ride after work...