Mesa Verde National Park, 1917, 1939 and today

"In what is now this Park, a Spanish exploring party discovered cliff houses in 1541. At that time the buildings had been abandoned for generations. No one knows how many centuries or millenniums had then elapsed since the Mesa was deserted. The age of these cliff houses has been estimated from five hundred to five thousand years. Modern discovery of the region appears to have been made by a government geological party in 1874." -- Enos A. Mills, Your National Parks, Houghton Mifflin, 1917 via Google Book Search.



Russell Lee photographs via Library of Congress Prints and Photographs Division, Farm Security Administration - Office of War Information Photograph Collection.
What everyone was looking at, via Flickr.

"It is true that their civilization was different from ours of to-day, and happily different from the European civilization of that time...They possessed a keen sense of right and wrong, and in ethics they may have averaged higher than the European." -- Mills