SH 33 was originally proposed on November 19, 1917, from El Paso to the New Mexico state line.

[2] On December 18, 1917, an intercounty highway was designated from Amarillo to Higgins.

[5] On March 19, 1919, another section of SH 33 was added from the New Mexico state line through Amarillo northeast through Panhandle then east through Wheeler and into Oklahoma, replacing the intercounty highway from Farwell to Canyon and the section of the intercounty highway from Amarillo to Pampa.

The section from Pampa via Wheeler to the Oklahoma state line was cancelled.

[11] On February 17, 1925, it had been moved to a new route from Pampa via Wheeler to the Oklahoma state line.

On February 26, 1930, it was rerouted to go west to Pampa instead of Miami, and it was extended east to Wheeler.