On July 15, 1935, the section west of Wimberley was cancelled. On September 22, 1936, SH 80 was extended to Karnes City, replacing a portion of SH 112. On September 26, 1939, SH 80 was extended southwest to the Atascosa–Karnes county line, replacing SH 312.
On July 15, 1935, the western section of Wimberley was cancelled. On September 22, 1936, SH 80 was extended to Karnes City, replacing part of SH 112. On September 26, 1939, SH 80 was extended southwest to the Atascosa–Karnes county line, replacing another route.