In April 1804, Jefferson formally asked William Dunbar to lead an expedition into the new Louisiana Purchase territory and informed him that he had assigned Dr. George Hunter as his "fellow-labourer & counsellor" on this "Grand Expedition." 

Early Troubles 

With an appropriation of $3,000 by Congress, the trip preparations immediately began . During the planning stages, both Jefferson and Dunbar became worried about the violent activities of Osage Indians in what would become Arkansas and Oklahoma. Because of his concerns for both safety and the success of the expedition, Jefferson wrote to Dunbar that he was afraid the Osage would delay their travel on the Arkansas River “and perhaps do worse.” Both Jefferson and Dunbar also had worries over possible Spanish resistance in northwestern Louisiana and northeastern Texas.

In June 1804, Dunbar wrote to Jefferson asking permission to attempt a trial run up a tributary of the Red River to a smaller river called the “Washita.” He wrote again on August 17, 1804 reporting he had heard of many “curiosities” along the Ouachita River, and referred to a location he called “the boiling springs”—present-day Hot Springs National Park.

As this new planned journey began, the group departed from St. Catherine’s Landing on the Mississippi River on October 16, 1804. The team consisted of thirteen soldiers, Hunter’s son, two of Dunbar’s slaves, and one of his servants. The nineteen men took an odd looking “Chinese-style vessel” that had been designed by Hunter in Pittsburgh months earlier. The boat proved to be unsuitable for river travel because its draft was too deep.

On December 3, 1804, Dunbar and Hunter confronted the greatest obstacle so far to their journey. Near what is today Malvern or Rockport, the group encountered a large series of rocky rapids, called “the Chutes.” Dunbar described the formations as looking like “ancient fortifications and castles.”

Through difficult efforts of maneuvering the boat through and over the rocks, the team finally freed themselves from the boulders and continued the journey. The roar made by the Chutes, according to Dunbar, was similar to the sound of a hurricane he had experienced in New Orleans in 1779.