In his book, Undaunted Courage, Stephen Ambrose notes the following translation sequence occurred when Lewis and Clark met the Wallawalla Indians in April 1806.
Lewis speaks in
English
George Drouillard or Francis Labiche, French Canadian soldiers in the expedition, translate this into
French.
Toussaint Charbonneau, a 45-year-old French Canadian trapper who speaks no English, translates this into
Hidatsa, a language he has picked up in the course of trading with the Indians.
Sacagawea, Charbonneau’s fifteen-year-old Shoshone wife who had been captured by the Hidatsa four years earlier, translates this into
Shoshone.
A Shoshone woman held captive by the Wallawallas translates this into
Wallawalla, a language related to Nez Perce.
This was considered an improvement over the sign-language they had been using with the Indians further west.