About sixty years have passed since the last comprehensive inventory of county records was undertaken in Oregon. In the late 1930s the Historic Records Survey, a project of the Works Project Administration, compiled inventories of unpublished government records in Oregon. These published guides as well as the unpublished data gathered for other counties served as important resources for the OHRP staff. Photocopies of Oregon Historical County Records Guide inventories are available at the Oregon State Archives in Salem. The county clerk's office and trial court administrator's office in each county have copies of the guide related to the particular county.
Additional copies are at many county historical societies and museums.