North Dakota State Flower The Wild Prairie Rose. - For highway travel south via U.S. highway # 85 See Milebymile.com Road Map Highway Travel Guide US #85 North Dakota / South Dakota State Line to City of Williston. Note US Highway #85 called CanAm Highway and the 'Old West Trail.' Pick up the trail of America's greatest legends in North Dakota, and you'll find yourself in a legendary adventure of your own. Lewis and Clark, Sakakawea, George Custer, Sitting Bull and Theodore Roosevelt lived out larger-than-life adventures here. Whether you follow in their footsteps and rediscover the past or blaze your own trail and discover what makes North Dakota legendary today, you'll find wide-open spaces and wide-open fun!