Oregon State University Libraries maintains a photography database they’ve christened The Pacific Northwest Stream Survey Photo Collection.
From their site -
…includes over 1000 field images taken between 1934 and 1945. These span 390 streams in the Columbia River Basin. U.S. Bureau of Fisheries Researches who took these photos looked at spawning and rearing habitat for Spring Chinook Salmon.
You simple click on a region highlighted on the map above and up pops a more detailed map with the locations of these (sets of) historic photos.
Some nifty photographic gems are buried in the collection.
Take your Friday afternoon fishy diversion activity to a whole new level; this counts as historical research.
Hat tip: Leigh at FinFollower.com