We camp up there 3-4 times a year. It's our favorite place to go. There's 8 CGs along the river. 1 (Pine Rest) is tent only. 1 (Gorge) has no water, the rest have water spigots scattered around. All the CGs are loops and each CG has sites that are next to the river. Only 2 take reservations, Smiling River CG and Camp Sherman. On weekends all CGs will be almost full. During the week its about 1/3 full. We've gone up on a thurs before a big 3 day weekend and have been able to get a spot in a non res CG. Coming up Friday night before a normal weekend is a gamble.
We are avid bike riders and love riding up there. There's forest service roads and bike trails all over. Our favorite ride is to ride from our CG up to hwy 20, cross the hwy and take the Suttle Tie trail to Suttle lake, then take Lake Creek trail back to our CG. About 20 miles RT.
There's a nice little store at the resort that has just about everything that you might need.
We have a 28' 5th wheel and can stay in most CGs up there. We see some larger (35') 5th wheels at Smilling River and Camp Sherman a lot.