What goes up, must come down. In this case, driving up Shafer Trail in Canyonlands National Park is much less frightening than attempting to descend. A broad mesa lies between the Colorado and Green rivers. This wedge shaped section of land is named Island in the Sky. Shafer Trail winds its way up a 1,500 foot sheer-walled mesa cliff, using a path with multiple, sharp switchbacks. This old cattle trail is one of the many exciting four-wheel-drive routes in the park.