Pinedale has all kinds of riding I used to ride there a lot growing up. You can either go to The Upper Green, which is always good from mild to wild, and you can ride Horse Creek (aka Blind Bull). Horse Creek has some very technical areas, and I would consider it to be more extreme than the Upper Green, but I would really suggest going to both! They're about the same distance from town. I've also heard great things about the Madres, but unfortunately I've never had the pleasure of riding there. Maybe this year my brother and I will go exploring and see what it's all about.
Another place I used to ride a lot was Lake Viva Naughton (South Hams Fork) outside of Kemmerer, I've always enjoyed riding there no matter what the conditions were. There's some pretty nice playgrounds, as well as some really nice drainage's/creek beds if you can get in far enough North.