Significant extension came on October 10, 1947, when SH 70 was extended to Perryton in the northern Panhandle; this was due to the realignment of US 62 between Matador and Ralls, bypassing Dickens, and the cancellation of SH 18 from Matador to Perryton. On February 12, 1948, US 277 was rerouted to a more westerly alignment between Abilene, Texas and San Angelo, Texas, and the section from just south of Blackwell to near San Angelo was transferred to that route.
On October 10, 1947, SH 70 was extended to Perryton in the northern Panhandle due to changes in US 62's alignment between Matador and Ralls, bypassing Dickens, and the cancellation of SH 18 from Matador to Perryton. On February 12, 1948, US 277 was rerouted to a more westerly path between Abilene and San Angelo, Texas, and part of that route included the section from just south of Blackwell to near San Angelo.