These photos are from a USGS rafting tour exploring the geology through the lower reaches of the Grand Canyon. I came across these while I was trying to decide whether or not to book a several day raft tour from Lee's Ferry to Lake Mead, and no, I haven't decided yet, but these pictures make it look like quite a beautiful journey. But once you enter the canyon, you're committed to completing the journey. Most raft trips through the Grand Canyon vary in length from 7 to 18 days, and the folks use paddle rafts, motorized rafts and dories. For more info.

One of the joys of National Park Service and USGS web sites is the terms and conditions/disclaimer. Virtually all of them say the materials and photos are in the public domain and available for anyone's use. So these will work for me until I can make the trip and get my own.