I really do enjoy Uwharrie, and the CROC guys do a good job with the Safari. The trails are great, and the weather has a real impact on drivabilty.
I will disagree about the street and AT tired vehicles being parked though. I have spent the last ten years driving those trails and driving with people on those trails when their are wet, dry, and covered with ice, and here is what I think is different about driving the wet trails with street or AT tires, pace. It is an issue of how quickly you can travel one of the trails when it is wet with those types of tires, and the trails that you choose to drive. On some of the trails stock tires will only get you there if you have very high, I once watched Mark Barber (94 Camel Trophy) drive a stock 97 up a wet Dutch John, driving skills. I certainly couldn't have done it.
This last URE, the trails were soaked and miserable having received 3' of rain and didn't dry out until mid afternoon, later on the north and eastern slopes, but I led a group of about 10 vehicles of which about 1/2 of the drivers had stock street tires on their vehicles, and they did a great job. I, or any body with any skill and tire with more traction, could have driven the trails in a third the time, but that isn't the point. It is more difficult, to be sure. It took a lot of individual coaching, and the were quite a few occasions when an attempt or 6 was required to continue, and it required patience from the other drivers, but it was great fun. I didn't drive that trip, and literally ran all of Slab Pile, and Wolfs Den both ways, but the folks that did drive their vehicles with the tires they had really felt like they accomplished something. I certainly thought they did.
I would like to add that mistakes can be a little costly though as the conditions can lead you in to real trouble so you need to check your risk tolerance, because regardless of tire choice, it is very easy to become 4300 pound toboggan.
Hopefully my schedule will let me get to this year's Safari!