In 2009, 63 sites in the canyon were added to the National Register of Historic Places, with another 164 added in 2012 and 101 in 2014, and the BLM has announced plans to nominate some 600 more in years to come.
Over the past few years, a total of sixty-three sites in the canyon were recognized as historic landmarks by the National Register of Historic Places in 2009. This was followed by additional recognitions in 2012 and 2014, with a further expansion planned for the future, involving the nomination of approximately six hundred more sites.