Located at the crossroads of the Cascade, Klamath, and Siskiyou mountain ranges, scientists have long recognized the outstanding ecological values of the Cascade-Siskiyou National Monument. The convergence of three geologically distinct mountain ranges resulted in an area with remarkable biological diversity and a tremendously varied landscape.  The Monument was originally established by presidential proclamation in June 2000 in recognition of its remarkable ecology and to protect a diverse range of biological, geological, aquatic, archeological, and historic objects.

In 2008, the BLM completed the Record of Decision and Resource Management Plan for the Monument. Land use decisions made in this plan include: land tenure zoning classifications; designations of vegetation management areas; visual resource management classifications; programmatic and site-specific decisions related to livestock grazing; decisions regarding transportation and access (except those mandated by the presidential proclamation); wildland fire management; recreation management; and management of rights-of-way and communication sites.

In 2009, the United States Congress designated the Soda Mountain Wilderness and it now has over 24,700 acres within the Cascade-Siskiyou National Monument. All of this wilderness is located in Oregon and is managed by the Bureau of Land Management (BLM).

In January 2017, a second Presidential proclamation expanded the original Monument and included habitat for populations of the endemic Jenny Creek ****** and Jenny Creek redband trout, as well as habitat for the Klamath largescale ******, the endangered shortnose ******, and the endangered Lost River ******.