D1  was closed when this agency, created in 1916, petitioned to allow climbing
D1 (Longs Peak):  In 1954, when National Park Service was petitioned to allow climbing on The Diamond they responded with an official closure. National Park Service: The National Park Service (NPS) is an agency of the United States federal government that manages all national parks, many national monuments, and other conservation and historical properties with various title designations. National Park Service:  It was created on August 25, 1916, by Congress through the National Park Service Organic Act and is an agency of the United States Department of the Interior.
National Park Service