The northern section of SH-37 runs 65.8 miles (105.9 km) from US-281 in Hinton to Sunnylane Road (former SH-77H) in Moore.

It runs in a zigzag pattern for four miles (6.4 km) to the southeast before crossing into Canadian County.

[4] Back in Caddo County, SH-37 runs three miles (5 km) south to the town of Cogar, where it joins SH-152 and turns to the east.

There, SH-152 turns to the north, and SH-37 joins US-81 for a one-and-a-half-mile concurrency to Minco, where SH-37 splits off and heads east once again.

The southeastern SH-37 begins where TX-37 crosses the Red River into Oklahoma, and heads north for two miles (3 km) to a junction with SH-98.