The westernmost segment begins east of
Watford City on
North Dakota Highway 23, and runs north its northern terminus at the Tobacco Gardens Recreation Area on the southern shore of Lake Sakakawea. The next segment of ND 1806 begins a few miles east-southeast of Tobacco Gardens and heads east before turning south and passing through Charlson. The southern end of this segment also ends at
ND 23. The third segment runs east–west, and begins at
ND 8 between
Halliday and
Twin Buttes. This segment parallels the southern shore of Lake Sakakawea before ending at
ND 200 southwest of
Pick City. The fourth and final segment of ND 1806 is largely north–south, with its northern end near the Oliver-Morton county border north of
Mandan and
Harmon. The highway intersects
Interstate 94 and passes through downtown Mandan before following the Missouri River south through Morton County and onto the
Standing Rock Sioux Reservation. The highway is concurrent with
North Dakota Highway 24 for much of its length in Sioux County, and breaks with Highway 24 north of the North Dakota/South Dakota border. After entering South Dakota, the highway continues as
South Dakota Highway 1806. ==History==