Brian Head is high elevation, and should be rideable if they don't have too much snow (top is over 11,000ft). Utahmountainbiking.com has details on trails, and you can either pay for shuttles or ride the lifts to get up top, for trails near the lifts. The trails are killer, look for TR's that GP_pilot or myself put together a couple years ago. Thunder Mtn is a couple hours off the 15 but may be cool enough to ride in the mornings, and definitely worthwhile if you haven't been.

skip S. Utah and just ride in Jackson area, my $.02.

I've ridden in Jackson Hole. There's a sweet trail that runs up and over the mountain where the ski resort is that overlooks the town. Can't recall the name of it, but the trail starts in a canyon to the side of the mountain and goes over the saddle and eventually dumps you out to the road that leads into Jackson from the south, so there's a little bit of pavement to return back to town. It does not go up the face where the ski trails are.

Geez, this description is lame! Check the bike shop for more info. That's who told me.

Navaho Lake between Brian Head, and Panguitch Lake has great camping, fishing, and riding all right from the camp grounds. It's at around 7500/8000ft so its not too hot and. Thunder Mt., Casto, and Loose Canyon, and Bryce Canyon NP are all pretty close as well. Carefull on the weekends as the Las Vegas Camping Crowd shows up but it is very open on the weekdays. They run shuttles from Brian Head that are, not to be missed, kick ass, rides. My favorite, Left Fork Bunker Creek shuttle.