The Dearborn – Ancient Interstate Highway

The Dearborn – Ancient Interstate Highway. A shortcut missed. ...we passed the entrance of a considerable river on the Stard side about 80 yds wide being nearly as wide as the Missouri at that place... This handsome bold and clear stream we named in honour of Secretary of war calling it Dearborn's river. – Meriwether Lewis, July 18, 1805 , The mouth of the Dearborn River is on the opposite side of the river approximately one-quarter mile upstream from this location. , The drainage of the Dearborn River provided a natural roadbed from the crest of the Continental Divide into the Northern Plains for the mountain nomadic Indian Tribes living west of the divide - this passage way was known to them as the "Road-to-the-Buffalo." It also provided a route from the Missouri River to the rivers on the Pacific side of the divide - thus the potential for a water route across the continent, a primary objective of the Corps of Discovery. , Lewis and Clark had been told of this route while wintering at Fort Mandan in 1804–1805, but were given sketchy details. On the night of July 17, 1805 the party camped downstream very near the present day Dearborn Inn. They failed to recognize the river's importance when they passed the mouth early in the morning of July 18th. During the winter of 1805-1806, at Fort Clatsop, Lewis and Clark determined that this was the river they had been given information concerning. Lewis returned along the "Road-to-the-Buffalo" in 1806. , Lewis and Clark named the river for Henry Dearborn, President Jefferson's Secretary of War.