Skip Navigation and banner
This site will look much better in a browser that supports web standards, but it is accessible to any browser or Internet device.
University of Wyoming

Rocky Mountain Herbarium (RM)


What is now called the Rocky Mountain Herbarium (RM) was founded by Aven Nelson in 1893 based on a collection of about 300 plants made by B. C. Buffum during the summer of 1892. By 1902 the collection had grown to 40,000 specimens. Since 1960, it has been housed on the third floor of the Aven Nelson Building. Over the years, the RM has grown gradually through the efforts of staff and graduate students in obtaining specimens from throughout the Rockies. Major spurts came with the integration of the George E. Osterhout (20,000 sheets in 1937) and Hapeman (30,000, 1951) herbaria. Since 1978 an intensive effort to inventory the flora of the Rocky Mountains has resulted in the addition of nearly 500,000 specimens. Over 5,000 type specimens are housed at RM. Total collections for RM currently stand at over 700,000.

The majority of RM's collections are from the Rocky Mountain Region as follows:

  • Wyoming: 333,000
  • Colorado: 181,000
  • New Mexico: 58,000
  • Idaho: 23,000
  • Montana: 17,000

An additional backlog of approximately 350,000 additional specimens await filing. The backlog is readily accessible as the hopper boxes are arranged by project and the contents are alphabetically arranged by family and species. For recent projects at least, all species of conservation concern have been removed and accessioned.