North of McKnight, the highway crosses the Salt Fork of the Red River.

[4] The highway bridges over the Elm Fork of the Red River about two miles (3.2 km) before crossing into Beckham County.

After crossing SH-33, SH-30 continues on for two miles (3.2 km) to its terminus at a local road at Durham.

On November 18, the highway was extended west along US-66, then south, setting its southern terminus at its present location at US-62 in Hollis.

[2] SH-30 still appeared as such on the 1938 state highway map, but with dashed lines, indicating the route was not maintained.

[2] The highway proceeded east from Hollis along US-62, then, at Gould, turned south along what was previously an unnumbered farm-to-market road.

On February 18, 1958,[2] the highway was extended to run west along US-62, then split off to the south two miles (3.2 km) east of the north–south Texas state line.

The highway then ended at a bridge over the Prairie Dog Town Fork of the Red River, the southern Oklahoma–Texas boundary.