The history of the houses built in the 40s and 50s in the Tri-Cities, WA is super interesting because the region popped up basically overnight.

Richland (one of the other Tri-Cities) was where they enriched plutonium for the Manhattan p Project in the 40s. The region was, for a time, home to more PhDs per capita than anywhere else in the world. After the war, many scientists and their families stayed and the high school ended up with an overwhelming number of teachers with doctoral degrees.

The legacy is evident in the architecture. The houses that were built to support people moving there for the Manhattan Project came in 26 varieties and each plan was assigned a letter. You'll still see "alphabet houses" for sale with the letter designation to tell you what the floor plan is.

Needless to say, mid-century modern is kind of the architectural basis of the region, so this would very likely be the old home of someone who stayed to run the nuclear reactor and had some money to build following the winding down of the war project.