Leaving Fort Clatsop, Oregon on March 23, 1806, the Corps of Discovery began their journey home.   Having survived a winter of sickness, monotonous diet, and dreary weather, the impatient explorers departed after gifting Fort Clatsop to a Clatsop leader. 

It had been almost two years since they had left Wood River, Illinois in May of 1804.  The explorers were backtracking across familiar terrain and their previous route, however they would alter their path after passing the great falls of the Columbia.  Trading canoes for horses the explorers continued their journey by land to the Walla Walla (Walula) Indians.  Camping among the tribe for two days, Chief Yelleppit informed them of an overland shortcut to the Nez Perce.  This route took the party across present towns of Waitsburg, Dayton, and Pomeroy, Washington.  Reaching the Snake River on May 4, they continued traveling up the north side of the river before settling into a camp on May 14, awaiting the snows to melt in the Bitterroot Mountains.  Their campsite was called "Camp Chopunnish", a word Lewis used for the Nez Perce, located near Kamiah, Idaho.

On June 10, they gathered their horses and proceeded on to Weippe Prairie.  Four days later Lewis reported in his journal, "we have now been detained near five weeks in consequence of the snows; a serious loss of time at this delightfull season for traveling. Every body seems anxious to be in motion."  The next morning they departed Weippe Prairie in an attempt to cross Lolo Trail.  On June 17 the disappointed explorers returned to the Prairie and hired an Indian guide from their nearby campsite of "Chopunnish".   On June 24 the party set out along with their three Nez Perce guides arriving at Traveler's Rest (near present Missoula, Montana) six days later. 

On July 3, 1806, the Corps of Discovery left  Travelers' Rest.  Captain Lewis and nine men went to pursue a direct route to the Missouri, then explore Maria's river. Captain Clark and the rest of the party went a new route to the Jefferson River, then descended to the Three Forks and then proceeded with a detachment party to explore the Yellowstone, while Sergeant Ordway, with nine men, descended the Missouri.          Map of Routes

Reuniting on August 12, at Reunion Bay near New Town, North Dakota, days later Lewis and Clark bid farewell to Sacagawea, paid Toussaint Charbonneau for his services and turned their canoes south, arriving in St. Louis 37 days later.