July 27, 2007

LAKE MEAD NRA, NV - Boats are moored at the Lake Mead Marina July 25, 2007 in the Lake Mead National Recreation Area, Nevada. A seven-year drought and increased water demand spurred by explosive population growth in the Southwest has caused the water level at Lake Mead, which supplies water to Las Vegas, Arizona and Southern California, to drop over 100 feet to its lowest level since the late 1960s. The National Park Service has been forced to close boat launches, extend boat ramps and move entire marinas to try to keep up with the receding water levels. Experts fear that because the water at the lake, the largest man-made reservoir in North America, isn't being replenished as fast as it's being used, the possibility exists that it could run dry in the next 10 years. (Photo by Ethan Miller/Getty Images)