Moraines of Wallowa Lake
According to a specific version of the general theory about Wallowa Lake's origin, a thirteen mile long glacier flowed out of the Wallowa Mountains more than 20,000 years ago during the latest major glacial period and completely overran the future townsite of Joseph well to the north of the present-day lake. As the Ice Age climate slowly relented, the glacier at first retreated hesitantly, leaving the concentric series of recessional moraines (immense ridges of boulders) which are clearly visible in this photo and which were deposited during intervals of renewed cold weather. When the cold climate finally threw in towel once and for all, the glacier began retreating too rapidly to allow significant morainal deposition (actually, underwater studies have disclosed minor ridges on the bottom of the lake, suggesting that the retreat was not totally without hesitation) and vanished in a geological instant, thereby leaving behind the dramatic hole that is filled today by a textbook-perfect specimen of a moraine-dammed lake. Had the retreat not been so sudden, the glacier might have slowly filled in this basin with recessional debris, leaving no place for a lake.
Today, according to a compelling school of thought, the biggest threat to the existence of this wonder is posed not by a return of the glacier but by a swarm of bulldozers and backhoes. People who value Wallowa Lake as it is might want to contact and assist the Wallowa Land Trust (www.wallowalandtrust.org) in its attempt to do something about the real danger that this special place will soon be divided up, sold off to the multitudes, and improved by bulldozers and backhoes.