The Oregon Historical County Records Guide is the result of the Oregon Historical Records Project (OHRP), funded by a grant from the National Historic Publications and Records Commission (NHPRC). The original inventory
conducted from September 1993 to September 1994.
Additional inventories began in 1998 to update the guide.
The work is patterned loosely on the first comprehensive inventory of county records undertaken in Oregon. In the late 1930s the Historic Records Survey, a project of the federal Works Project Administration, compiled inventories of unpublished government records in Oregon. Guides, titled "Inventory of the County Archives of Oregon," were published for 13 Oregon counties: Benton, Clatsop, Coos, Hood River, Josephine, Klamath, Linn, Morrow, Multnomah, Tillamook, Umatilla, Wasco, and Washington. These published guides as well as the unpublished data gathered for other counties was used in this guide.