@CNN: As Grand Canyon National Park turns 100, this photographer is worried about its preservation. He hiked its entire length — some 750 miles — in an effort to save it. https://t.co/8YYCJjCdPi https://t.co/ZNIOfL3zPq

@CNN: As Grand Canyon National Park turns 100, this photographer is worried about its preservation. He hiked its entire length — some 750 miles — in an effort to save it. https://t.co/8YYCJjCdPi https://t.co/ZNIOfL3zPq