The Yellowstone Trail Association was formed in 1912. The founders envisioned a fully transcontinental route allowing automobiles to travel coast to coast across the United States. The motto was “A Good Road from Plymouth Rock to Puget Sound”. It’s interesting that unlike many ideas, the actual route was begun in the Midwest using existing roads and upgrading them to allow automobile travel. In 1912 a route from Ipswich to Aberdeen, South Dakota was completed. In 1913 it was continued west to Yellowstone National Park and east to the Twin Cities in Minnesota, along a route from Ortonville through Glencoe, Norwood, Young America, Waconia, Excelsior to Minneapolis and St. Paul. The automobile friendly route reached Seattle (Puget Sound) in 1915 and Plymouth Rock by 1919.