When the National Park Service was created in 1916, several nonprofit organizations (cooperating associations) were formed to support park programs and projects not covered by government funding. By 1936 cooperating associations were formally recognized by Congress, which passed laws enabling them to operate in the national parks. In 1938 the Southwest Monuments Association (later known as the Southwest Parks and Monuments Association (SPMA)) was created by the National Park Service and was committed to supporting the education and preservation of 18 national monuments across Arizona and New Mexico.
In 2002 the SPMA was renamed the Western National Parks Association (WNPA). The association is located in Tucson, Arizona and now services 66 locations in 12 states and donates over $4 million annually to its national park affiliates. Donations are raised through bookstore sales, membership support, book and publication development, research funding and other educational activities.
The Hubbell Trading Post was sold to the National Park Service in 1967. It is still an active trading post run by the non-profit organization the Western National Parks Association (formerly the Southwest Parks and Monuments Association) for the Park Service.
The bulk of the collection contains correspondences and financial files. The photographs of rugs and research related materials are contained in Hubbell Trading Post series. The documents from different committees are organized by committees and arranged alphabetically in SPMA series. The meeting minutes and agenda and publication are included in SPMA as well.