Created in 1926, the route connected several small communities in the northwest corner of the state near the Oklahoma border.

[6] On the 1936 map, even the Summers to Siloam Springs segment has been renumbered State Road 59, deleting the entire route.

[7] However, the State Road 99 designation returned the following year, now between Siloam Springs and Missouri.

[8] Following the restoration of the designation in 1937, State Road 99 remained unchanged for many years.

A minor extension took place following rerouting of Highway 68 in Siloam Springs on November 8, 1961.