Washington County Historical Organizations
- Afton Historical Society Museum
- Denmark Township Historical Society
- Forest Lake Area Historical Society
- Gammelgården Museum
- J.W. G. Dunn Research Library, St. Croix Watershed Research Station – associated with the Science Museum of Minnesota, this organization maintains a history of the St. Croix River and has a collection of river photographs from the Dunn family
- Minnesota Transportation Museum – this popular group operates historic trains in the northern part of Washington County on the Osceola & St. Croix Valley Railway
- South Washington Heritage Society
- St. Croix Collection – Stillwater Public Library
- Washington County Historic Courthouse – a county-owned and operated facility
- Washington County MNGenWeb Project page – this international genealogy project is based at the local county level and this site represents Washington County, Minnesota
- Woodbury Heritage Society – Woodbury, Minnesota