It runs from U.S. Highway 138 (US 138) in rural Logan County north to Nebraska Highway 19 (N-19) at the Nebraska state line.

SH 113 begins at a junction with US 138 approximately nine miles (14 km) northeast of Sterling and proceeds north for almost 16 miles (26 km) before passing through the small town of Peetz and continuing a further three miles (4.8 km) northeast to the Nebraska state line, where the road becomes N-19.

The route was established in the 1920s with its current routing from U.S. Highway 138 to Nebraska Highway 19 at the Nebraska state line.

[2] The entire route is in Logan County.

[3] Media related to Colorado State Highway 113 at Wikimedia Commons