There is a road that runs to the east of current US 69-75 that appears to be an old alignment. Was it a pre-US highway road or was it part of the original US 75? It has a double S curve railroad underpass at the north end. Part of it is marked Old US 69 on Google Maps and part of it as "Old Hwy," but we all know how reliable Google Maps is.
Yep. From the 1940 census (http://1940census.archives.gov/search/?search.census_year=1940&search.city=&search.county=Atoka%20County&search.page=1&search.result_type=map&search.state=OK&search.street=#city=&filename=m-a3378-00049-00043.tif&type=map&county=atoka-county&state=OK):
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