The highway is located in Galveston, Chambers, and Jefferson counties and also serves the communities of Hamshire, Fannett, and Cheek.

The route number was originally assigned over a portion of the current SH 16 between Fredericksburg and Comanche in Central Texas during the late 1920s.

By the end of the decade, the highway received its current High Island to Beaumont configuration.

[3] The highway proceeds to the north climbing up a salt dome[4] where the central portion of High Island is located.

FM 364 branches off to the north as the highway enters Beaumont where it as known as Fannett Road.

[10] SH 124 was originally designated along a route from Fredericksburg to Comanche passing through Llano, San Saba, and Goldthwaite on September 9, 1927.