It was once one of the longest state highways in the Oklahoma road system, but now has a total length of 134.4 mi (216.3 km).

US-177 runs roughly on top of the previous SH-18 between Dickson and Asher, Oklahoma, therefore only a few small segments of the original highway remain through that stretch.

The existing old highway runs parallel west of US-177 for about a mile, before terminating short of the Canadian River.

Originally, the highway continued straight for about another 0.5 miles (0.80 km) (taking it over the river) before veering east and then back north.

The existing highway picks up again after a second removed bridge and 0.7 miles (1.1 km) before intersecting with SH-39 south of Asher.

North of Pearson is the Salt Creek Bridge, a 120' long OSHC standard design, built in 1930.

The highway is interrupted once because of the removed Little River Bridge before reaching the Brooksville, Oklahoma area.