Left, Pre-World War I advertisement by the Burlington System to the Cody Road. Right, 1924 Burlington Brouchure cover for Cody Road. Note that the left cover features a Stanley Steamer and the right covers use a post-war White touring car. Prior to 1916 motor traffic was not permitted within Yellowstone Park. The Northern Pacific and the Union Pacific's subsidiary the Oregon Shortline had, as a result a practical monoply on traffic to the Park. With the opening of trafic to the Park, the Northern Pacific as previously noted and the Burlington System began advertising. The Burlington was far more agressive in its adveertising and featured the Cody Road as an attraction unto itself. The Burlington also offered the opportunity to come into the Park by wither Gardner or Cody and exit by the other city. Burlington magazine advertisement, 1923 Many of the later ads featured a tag line, "If You don't see the Cody Road you don't see Yellowstone." Advertisements for Burlington System Avalanche Peak is to the west of Sylvan Pass. Burlington Ad featuring Shoshone Reservoir, 1940. Left, 1937 Burlington cover featuring Shoshone Dam, 1937. Right, 1940 Burlington cover featuring Sylvan Lake Next Page: Yellowstone National Park.