Its longest section begins at SD 273 and runs along the Missouri River nearly its whole length, serving Pierre.

After one mile of concurrency, SD 1806 splits from US 14/SD 34 and heads north, passing by the Fort Pierre Chouteau National Historic Landmark and remaining parallel with the Missouri River.

SD 1806 continues west and remains parallel with the Missouri River until reaching Sansarc Road.

The route continues northwest and ends at an intersection with Minneconjou Road south of Mission Ridge.

Although unsigned, it provides access to the town of Wakpala, South Dakota, located in the Standing Rock Indian Reservation.