In North Eastern Utah, about an hour outside of Vernal you will find some very unusual geological formations that date back to 38-55 million ago. If you are in North Eastern Utah I recommend that you take a few hours and check out Fantasy Canyon.
During the hot summer months it is best to go early in the morning before the sun is at it's hottest. The trails are easy, it is only about a mile around but wear good shoes. Wear sunscreen and bring plenty of water.
You can find more information and directions to Fantasy Canyon here.