William Clark`s Map of the Lewis and Clark Trail

Across the Rockies Westbound

Westbound: Westbound: Three Forks to Clearwater River, 07/29/1805 through 10/07/1805.
Eastbound: Will need to be covered separately, as they divided into separate groups on the return trip.

On Google Maps.

Captain Clark's map, with overlays by myself.

At the headwaters of the Missouri River, the river branches into three forks, which is why the closest town today is called Three Forks, Montana. The captains chose the westernmost fork, which they called the Jefferson River (as it is still known today). Having coming thus far in canoes, and knowing that they would need horses to portage their supplies across the Rocky Mountains, they searched for Shoshone Indians. At a meeting with the Shoshones, Sacagawea suddenly ran to their chief (who was called Cameahwait) and started to hug him and cry profusely. She had recognized that he was her brother, whom she had not seen since she was kidnapped by the Hidatsas five years earlier.

That location is known as Camp Fortunate, for this turn of events helped the captains establish good relations with the Shoshones, whom they desperately needed for their horses and to guide them across the Rockies.

To the immediate west of Camp Fortunate is a mountain range, known today as the Beaverhead Mountains. The expedition crossed those mountains at a place known as Lemhi Pass. The significance of this spot is that it's on the Continental Divide; that is where the expedition entered the Columbia River drainage.

Continuing westward, the captains wanted to travel by water if possible. Despite the warnings of Cameahwait, they explored the Salmon River and found that it was not navigable. A Shoshone man (who they called Old Toby) volunteered to guide them across the Rockies, and they proceeded with him northward to a place they named Traveler's Rest. The journey from Traveler's Rest to the eastern edge of Weippe Prairie took nine days, during which they nearly starved to death. Cameahwait had warned them of that also.

They found Nez Perce villages on the far side of the mountains, traded with them for supplies, and crossed Weippe Prairie by land. Their voyage continued by water after reaching the Clearwater River. The spot where they reached the Clearwater is marked by the westernmost X on the map above.