Here's a link to pictures from the last time I was there. It had rained a lot, so it was extremely muddy. It would be a lot more fun dry.

http://home.sprintmail.com/~tcdesign/roys_june6/roys.htm

I ended up not going this weekend - I did a lot of landscaping instead. But anytime anyone wants to go - next weekend for example - I would be up for it. The terrain is extremely varied. A lot of hillclimbs, water crossings, and some pretty hard stuff we didn't even try. There are a lot of small areas where you can just play around to get the feel for what your truck can do (the mogul area for instance). You really don't need any modifications to have fun there, however, I would recommend removing your steprails, and if you feel like it, removing your rear swaybar (I've had mine off for 2 years and don't notice it at all). If its as muddy as it was in these pictures, more aggressive tires would definitely help too.

-Tim