In 1804, a cadre of explorers left Natchez, Mississippi, seeking to learn more about the Ouachita River and the celebrated hot springs of the Ouachitas at the request of President Thomas Jefferson. This meant that Lewis and Clark were not the only explorers of the United States’ huge, newly-acquired parcel of land called the Louisiana Purchase. William Dunbar of Natchez and George Hunter of Philadelphia led the excursion up the Ouachita, constituting the first American investigation of its new territory. Their reports pertaining to the river’s environs provide some of the earliest descriptions of the Ouachita River region, including the area that would become Clark County.
Richter, Wendy Bradley, "Dunbar and Hunter Expedition" (2016). Articles. 241.