Formulate an answer to this elaborate question: David Lee DeHarport was a photographer and anthropologist primarily known for his photographic work in Colorado's eastern plains region and his archaeological survey work of which location in northeastern Arizona, it is within the boundaries of the Navajo Nation and lies in the Four Corners region, and was established on April 1, 1931 as a unit of the National Park Service?
A:
Canyon de Chelly National Monument