Founded in 1946, it was one of the primary natural history museums in the state of Washington in its early years and has continued to the present to remain active in building up its collections.
By then, a herbarium collection, also started by Slater, had been added to the mix, and the museum took on an increasingly important role in the curriculum of the Biology Department.
In 1968, the museum was moved to new quarters in Thompson Hall, with offices and expanded spaces for specimen preparation and storage.
By that time, it was one of the pre-eminent natural history museums in the Pacific Northwest, under the directorships of Gordon Alcorn and then Terrence Mace.
In 2004, the museum was moved to new quarters in a central location in Thompson Hall, and the incoming director, Peter Wimberger, obtained a National Science Foundation collections improvement grant to replace wooden with metal cases.
As of December 2024, the museum's research collections totaled 31,363 mammals, 28,165 birds, 3,293 reptiles, 4,792 amphibians, 16,010 insects, 1,345 mollusks, 13,843 plants, 10,795 paleontology specimens, and about 4,000 rocks and minerals.
The collections provide specimens for a wide variety of research projects and are used in numerous University of Puget Sound classes.
PSM specimens are used as sources of DNA and measurements of stable isotopes in the inert tissues of feathers and hair.
At present, all of the vertebrate and plant collections are represented in the online databases of the Global Biodiversity Information Facility, Integrated Digitized Biocollections, Symbiota, and the Consortium of Pacific Northwest Herbaria.