North Dakota Highway 22 Sign, circa 1955

In 1923, North Dakota became one of the first states to adopt a uniform system for numbering and marking state highways. The state used the profile of the legendary Tacankpe Luta (Red Tomahawk), Lakota (Sioux) (c. 1850-1931) on its highway signs. In 2016, North Dakota's Department of Transportation switched to an outline of the state for its highway markers and began removing the older versions.