Turtle Mtns., ND

This image from NASA Terra spacecraft shows the Turtle Mountains, which straddle the US-Canada border in central North Dakota. Underlain by 55 million year old sandstones and shales of the Cannonball Formation, the upland surface was sculpted by glaciations. Due to the mountain's 150m elevation above the surrounding lowlands, glacial ice tended to stagnate, forming thousands of lakes and sloughs. The image was acquired May 19, 2006, covers an area of 43.5 x 53.1 km, and is located at 49 degrees north, 100.1 degrees west. http://photojournal.jpl.nasa.gov/catalog/PIA19435