The highway connects Ardmore to Madill as a more northerly alternate to US-70, much of which SH-199 is an old alignment of.

After leaving Ardmore, the highway continues along a due east course that takes it through the unincorporated places of Dripping Springs and Caldwell Hill.

Shortly after this junction, the two highways cross into Johnston County, where they pass through the town of Mannsville.

The highway then passes the Fort Washita historic site before ending near Brown, Oklahoma at SH-78.

[2] On July 7, 1984, US-70 was relocated between Interstate 35 (I-35) in Ardmore and Madill, shifting it south onto its present-day alignment.