On January 23, 1918, an intercounty highway was designated from Greenville to Decatur.

[2] On February 19, 1918, another intercounty highway from Pecos via Tahoka to Jayton was designated.

[3] On August 19, 1918, the Greenville-Decatur intercounty highway was extended to Cooper.

[4] SH 39 was originally proposed on January 21, 1919, as a route stretching from the Oklahoma state line north of Paris to New Mexico, partially along these intercounty highways.

On August 16, 1920, the section from McKinney to Decatur was cancelled and redesignated as an intercounty highway.