In February 1805, she gave birth to their son, Jean Baptiste Charbonneau (nicknamed "Pompey"), at Fort Mandan in present-day North Dakota.
Lewis, George Drouillard, John Shields, and Hugh McNeal left Clark and the rest of the expedition on the Jefferson River and set off overland toward the divide in search of the Shoshones.
They discovered Cameahwait's small band camped on a tributary of the Salmon River shortly after crossing the divide at Lemhi Pass, just north of what is now Tendoy, Idaho.
Lewis eventually returned with Cameahwait and more than a dozen other Shoshones to the Missouri River drainage, where they met Clark, Sacagawea, and the rest of the expedition.
Cameahwait's band ultimately traded several dozen horses to the expedition and helped them portage most of their supplies over Lemhi Pass.