When SH 195 was redirected north of Florence to Killeen over RM 440 on January 27, 1988, this portion was redesignated as SH 138.

It two lanes wide and travels east with some curves passing through no incorporated municipalities.

About 0.6 miles (0.97 km) later, it ends at an interchange with SH 195 which opened in 2014 as a part of improvements made to SH 195 corridor.

[1][3] SH 138 was previously designated on July 31, 1929, as a short connector route in Childress County from near Buck Creek to the Oklahoma state line[4] along what would shortly be cosigned with U.S. Highway 62.

Media related to Texas State Highway 138 at Wikimedia Commons