FILE - In this Saturday, May 21, 2011 file photo, tourists photograph Old Faithful erupting on schedule late in the afternoon in Yellowstone National Park, Wyo. Lower gas prices and other indicators ... more 
FILE - In this Saturday, May 21, 2011 file photo, tourists photograph Old Faithful erupting on schedule late in the afternoon in Yellowstone National Park, Wyo. Lower gas prices and other indicators point to plenty of out-of-state visitors coming to Wyoming to enjoy national parks and other attractions this summer, tourism officials say. (AP Photo/Julie Jacobson, File) less 
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Associated Press | Photo By Julie Jacobson, File
Tue, May 26, 2015 6:51 PM EDT