Arches National Park, Utah & Canyonlands National Park, Utah both have excellent 4 x 4 roads. In fact, the town of Moab, Utah is kind of a 4 x 4 hub. Inside and outside of the park there are all kinds of degrees of roads to take. For beginners I recommend the Potash Road, to the Shafer trail (with a short side trip to Mussellman Arch on the White Rim Trail) from Moab, Utah up to Canyonlands, Island in the Sky District, then stop at Dead Horse State Park before taking Long Canyon back to Moab.

Capitol Reef National Park and Dinasour National Monument both have 4 wheel drive roads.

Here are some websites with information on 4 wheel drive roads in Utah.

http://www.discovermoab.com/fourwheel.htm

http://www.utah.com/offroad/index.htm

http://www.4x4now.com/mu4wd.htm

Utahtea