In this photo taken Thursday, May 26, 2011, Yosemite National Park swift water rescue rangers practice in the raging Merced Rive in Yosemite National park. A historic Sierra Nevada snowpack is making ... more 
In this photo taken Thursday, May 26, 2011, Yosemite National Park swift water rescue rangers practice in the raging Merced Rive in Yosemite National park. A historic Sierra Nevada snowpack is making Yosemite National Park's springtime spectacle of cascading waterfalls especially beautiful and dangerous as the park welcomes visitors for one of the busiest weekends of the year. (AP Photos/Tracie Cone) less 
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Associated Press
Sat, May 28, 2011 12:45 PM EDT