FILE - In this Aug. 3, 2016, file photo, a large bison blocks traffic as tourists take photos of the animals in the Lamar Valley of Yellowstone National Park in Wyo. Park administrators appear to have... more 
FILE - In this Aug. 3, 2016, file photo, a large bison blocks traffic as tourists take photos of the animals in the Lamar Valley of Yellowstone National Park in Wyo. Park administrators appear to have lost ground on a 2009 pledge to minimize cell phone access in backcountry areas. Signal coverage maps for two of Yellowstone's five cell phone towers show calls can now be received in large swaths of the park's interior such as the picturesque Lamar Valley. The maps were obtained by a Washington, DC-based advocacy group, Public Employees for Environmental Responsibility. (AP Photo/Matthew Brown, File) less 
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Associated Press | Photo By Matthew Brown, File
Thu, Sep 29, 2016 3:06 AM EDT