The Lewis and Clark Expedition, officially the Corps of Discovery, traveled through what is now South Dakota from August 21 to October 14, 1804, and from August 21 to September 4, 1806. During its time there, the expedition recorded numerous animals, plants, birds, and fish previously unknown to science, including the prong horn antelope, which they called goats, the prairie dog, which they called barking squirrels, the mule deer, coyote, great gray wolf, prairie rattlesnake, northern jack rabbit, a different kind of porcupine, and the black billed magpie, which had been thought to exist only in Europe. The party also met a number of Indian tribes, giving gifts and making speeches about the great white father in Washington, and although there were a few tense moments, there were no battles with the tribes encountered in present-day South Dakota. In the Mobridge area, the expedition arrived on October 8, 1804, at the mouth of the Grand River, called Wetarhoo by local tribes. A short distance upstream, two men found an Arikara village on an island about three miles long, covered with fields where the Arikara raised corn, beans, potatoes, squash, and tobacco. Several Arikara and French traders who spoke Arikara watched the boats pass, and the explorers learned of two more Arikara villages upstream. Gifts were exchanged, with the Arikara providing corn, beans, and squash, and the captains spent the next few days meeting with the Arikara as well as some Cheyenne and Pawnee camped nearby before the expedition set out again on October 13, 1804.