During X-mas week last year I was off work and rode Greenleaf State Park; here's a few pic's from this ride.You can see in the first pic that it was cold enough for ice to form on the creeks.
In the second pic you see a little sign that says caution; it means it. There's a steep downhill with some tight switchbacks on it. (On this day I pushed up it.) 
Greenleaf is an awesome place to ride. It's way technical in spots, nice and flowing in others. Once you go past Mary's Cove it's freakin' ridiculous on the technical scale.
I like signs like this one; it lets you know right up front what this is all about.
I've had a lot of fun riding this trail in the past and would recommend it to anyone with some endurance and an adventuresome spirit. Also, I do not recommend a heavy night of drinking the night before this ride. I've seen the damage it can do to a person and it's not pretty. (Right Buddy?)
Oh, I almost forgot, here's the "official" entrance to the trail. (I say official because the 1st mile to get here is some of the hardest trail I've ever ridden.) 
