Yampa River, Utah
Credit: James Kaiser / Oars

Since there are so few dams upstream of the Yampa canyon in Dinosaur National Monument, the three- to six-day long, Class III-IV run can only be undertaken into June most years – after that the river is too low. This year the watershed boasts 25 percent more snowpack than an average year so folks should be able to enjoy the big, cresting waves, sheer 1,000-foot sandstone walls and beach camping into early July. Private parties must enter a lottery to win one of only two daily launches, but $849 will buy you a spot on most any of OARS' seven four-day trips.