Running the Colorado River through Grand Canyon is a sublime experience. The enormity of the canyon is such that often one cannot even see the rim. As the river descends through geologic history boaters become familiar with the rock layers representing epochs of the past. This journey through time climaxes in the inner gorge, where red granite intrudes the two-billion-year-old Vishnu schist. Long pools of placid flat-water are interspersed with giant wave trains and powerful hydraulics that dwarf even an 18ft raft. These high volume rapids frequently flip paddle and even oar rafts, but not to worry—the high volume and low gradient of the Colorado make it a fairly safe river to swim.

Any veteran of Grand Canyon will tell you that the best part of a Colorado River trip is hiking. Slot canyons beckon around every bend, many of which hide springs, fern grottoes and travertine waterfalls. The warm side creeks are a delightful contrast to the super-chilled river water that comes out of the bottom of Glen Canyon Dam.

In addition to the natural history of the Canyon there is a rich human history as well—spanning from the mysterious Anasazi cliff dwellers to 18th century explorers and 19th century thrill-seekers who ran the river before us. Following along with the written record about the Grand Canyon adds a great deal to a river trip there.