Matthew B. Gilmore
Recently published articles make much of the mystery behind the naming of Oklahoma Avenue: https://www.enidnews.com/news/state/oklahoma-avenue-thrives-despite-mysterious-history/article_07675fc8-7a66-5744-ac15-763d2d2b6d33.html and https://nondoc.com/2019/09/27/oklahoma-avenue-mysterious-history/
“…it has an untraceable history.
In 1981, the Tulsa World published a story about the lack of documentation regarding when and why Oklahoma Avenue received its name. Thirty-eight years later, the mystery remains unsolved.
“All the 50 states have diagonal streets named for them here, and presumably, there’s a record somewhere showing the naming,” the Tulsa World reported. “But no one seems to know just when Oklahoma was honored with a street.”
Frankly this is just silly–it’s never been a mystery or insoluble*.
Between 1893 and 1908 the groundwork of the entirety of Washington’s street network was laid out in the “Permanent System of Highways.” When the streets were mapped, they were named. They may never have been built, but they were named–read more here: https://matthewbgilmore.wordpress.com/2015/06/29/the-highway-plan-in-the-district-of-columbia-the-permanent-system-of-highways-for-the-district-of-columbia/ AND here: https://matthewbgilmore.files.wordpress.com/2018/01/portolan98-spring-2017-olmsteds-with-cover.pdf
This 1914 map (excepted above): https://www.loc.gov/resource/g3850.ct004507/?r=0.599,0.168,0.214,0.106,0 shows a massive Oklahoma Avenue (proposed) angling from C St NE in Rosedale and Isherwood–all the way out to what is now Fort Lincoln (formerly the U.S. Reform School–nice blog post by Robert Malesky here: https://bygonebrookland.com/2017/10/09/a-home-for-americas-bad-boys/
One can read mentions of Oklahoma Avenue as early as 1907 in the Evening Star.
By 1921 Cool Spring Road and Oklahoma Avenue were merging on the maps, with the creation of Anacostia Park and realigning of Oklahoma Avenue. https://www.loc.gov/resource/g3850.ct004468/?r=0.642,0.208,0.126,0.062,0 Creation of the Arboretum required the closing of the proposed (paper street) Oklahoma Avenue.
In 1926 additional changes to the Permanent System were being made in the area of Cool Spring Road and Oklahoma Avenue according to news accounts. Tweaks were being considered in 1929 Evening Star and 1931 Evening Star.
The diminution of Oklahoma Avenue from a grand avenue spanning several miles from C Street to Fort Lincoln is completed by the 1930s. This 1939 map shows what’s close to the current situation https://www.geographicus.com/P/AntiqueMap/DCHighways-surveyor-1939 — with what was Cool Spring Road renamed Oklahoma Avenue. For maps documenting the final renaming of Cool Spring Road one needs to consult the maps in the DC Office of the Surveyor.
*Mysteriousnesses about Washington, DC are perpetual favorites in the press.