At Travelers' Rest on the morning of July 3, 1806, the captains split the Corps of Discovery in two. Clark would lead his 20-man contingent back to Fortunate Camp on the Beaverhead, with Sgt. Pryor and six men herding their 50 horses, while the captain accompanied the six canoes as far as the Three Forks. From there, Sgt. Ordway and nine other soldiers would paddle the canoes down to White Bear Islands, while Clark and the remaining ten men would mount the horses and ride up the Gallatin River, through Bozeman Pass to the Yellowstone River at the big bend, and proceed downriver until they found large enough trees to make canoes. Thereupon, Sgt. Pryor and two helpers (it turned out to be three) would drive the horses on ahead to the Knife River villages, leave some there, take the rest 100 miles north to Fort Assiniboine and give them to Hugh Heney to seal a contract, and meet the rest of the Corps at the villages on the Missouri.
Lewis, meanwhile, would follow the Blackfoot River back to White Bear Islands above the Falls, choose six volunteers (ultimately he took only three) with him to explore the upper Marias River, leaving the rest to await Ordway's arrival with the canoes. Sergeants Ordway and Gass would supervise the portage of the canoes back around the Falls, and would pick up Lewis and his detail at the mouth of the Marias. The whole party, except for Sgt. Pryor and his helpers, would rendezvous at the mouth of the Yellowstone about the first of August.
In large part, the gamble was calculated to seize victory from apparent defeat, namely the proven absence of a viable link between navigable waters of the Missouri and those of the Columbia. During that month they would divide their 31-gun force into a succession of practically defenseless details that would disperse the Corps into an area some 122,000 square miles in extent. Those little units would sometimes be separated by more than 250 straight-line miles across mountains, plains and rivers, perhaps populated or frequented by people whom friendly Indians had taught them to fear. And they were betting their lives that they would all meet again where the Yellowstone joined the Missouri. In the meantime it was anybody's guess what the benefits of their bold excursions would be.
As they took their leave from one another at Travelers' Rest, Clark was stoically reticent, while Lewis "could not avoid feeling much concern." The other journalists were noncommittal. We can only imagine how strong were the bonds of mutual wishes for success and safety. If there were spontaneous prayers uttered aloud, we are told nothing of them. As the days with their discoveries, turns of fortune, disappointments, adventures and misadventures succeeded one another, the men's private thoughts must have been equally divided between desire for home and hope for their comrades. Clark and his party reached the agreed-upon meeting place on the third of August. Lewis was not there. Anxiety must have risen steadily in their breasts, as well as in those of Lewis's men, hour by hour for nine more days, until 10:00 a.m. on August 12 when at long last they were all joyously reunited.
Sergeant Gass appended the benediction, as if to himself: "(thanks to God)."
Funded in part by a grant from the National Park Service, Challenge-Cost Share Program