A national preservation organization recently named two Arizona locations — the Grand Canyon and Oak Flat — among the 11 most endangered historic places in the U.S.

The National Trust for Historic Preservation, a privately funded nonprofit group, had the following to say about the Canyon:

A sacred site for numerous Native American tribes as well as a National Park and a World Heritage Site, the Grand Canyon is threatened by encroaching development proposals ranging from uranium mining to elaborate tourist resorts that would forever mar this beautiful and sacred place. Not only would these proposals threaten the grandeur and majesty of the Grand Canyon, they could also disrupt an underground aquifer that is the main water source for the region.

Of Oak Flat near Superior, the trust had this to say:

Oak Flat is a sacred site to the San Carlos Apache and other Native American tribes. A land exchange that was included in the National Defense Authorization Act of 2015 would open the site up to mining. Protected in the past by Presidents Eisenhower and Nixon, Oak Flat houses many cultural resources including archaeological, historical, and gathering sites.

The group has been producing its list since 1988 and says it's intended to raise awareness of the threats facing America's greatest treasures.

Photo: Judy Graham | Grand Canyon