The International Peace Garden straddles the international Boundary between North Dakota and the Canadian province of Manitoba. In 1956 the North Dakota Motor Vehicle Department, on its own initiative, placed the words “Peace Garden State” on license plates; the name proved so popular that it was formally adopted by the 1957 legislature (North Dakota Century Code (NDCC), Section 39-04-12).

“Flickertail State” refers to the Richardson ground squirrels which are abundant in North Dakota. The animal flicks or jerks its tail in a characteristic manner while running or just before entering its burrow. In 1953 the Legislative Assembly defeated Senate Bill (S.B.) No. 134 that would have adopted the Flickertail facsimile as the official emblem of the state.

“Roughrider State” - This name originated in a state-supported tourism promotion of the 1960s and 70s. It refers to the First U.S. Volunteer Cavalry which Theodore Roosevelt organized to fight in the Spanish-American War. In fact, the "Roughriders," which included several North Dakota cowboys, fought dismounted in Cuba due to logistical problems. In both 1971 (House Bill No. {H.B. No.} 1383) and 1973 (G.B. No. 1443) the Legislative Assembly defeated bills intended to change the words Peace Garden State on state license plates to Roughrider Country. source: http://www.state.nd.us/demographics.html