"The Native Americans do not know for certain what Happened with Sacajawea after her return to the Lemhi River Valley. ... Many of the Lemhi Shosone believe that Sacajawea died at age 24 in South Dakota. ... Many historians call Sacajawea the most important woman in American History. ..." What Happened After the Lewis and Clark Expedition? - Sacajawea and the Lost Grave   Shoshone Woman