This map is dated April 5, 1919. It appears to show an early Oklahoma state highway numbering system. This system is unrelated to the 1924 system that is shown on other maps from the same archive. Were these routes signed in any way?
https://oklahoma.gov/content/dam/ok/en/odot/maps/state/pdfs/map-state-1919.pdf
(https://oklahoma.gov/content/dam/ok/en/odot/maps/state/pdfs/map-state-1919.pdf)
(https://i.imgur.com/Wptt1NL.png)
(https://i.imgur.com/PvDm89B.png)
Nice find. Looking at areas I am familiar with, it seems they are naming section line roads as routes.
Did the resolution pass the legislature? If so, does it define the routes in words?
It seems that the resolution passed with a full description of the routes (https://babel.hathitrust.org/cgi/pt?id=uc1.a0001936848&view=1up&seq=479) but the constitutional amendment was defeated by the public (https://books.google.com/books?id=LsAGAQAAIAAJ&pg=RA1-PA54&dq=%22senate+joint+resolution+no+10%22&hl=en).