Great Plains Studies, Center for


Date of this Version

Winter 1981


Great Plains Quarterly Vol. 1, No. 1, Winter 1981, pp. 39-53.


Copyright 1981 by the Center for Great Plains Studies, University of Nebraska-Lincoln


One of the curious twists of Great Plains history is that the first accurate eyewitness map of the Missouri River in what is now North and South Dakota-the historic home of the Mandan, Hidatsa, and Arikara Indians and of their nomadic neighbors-was produced by a Welshman who had come to the United States to seek evidence for something that never existed: the illusory "welsh Indians." The inquisitive welsh explorer, John Thomas Evans (1770-99), did not find what he came to discover, but he produced what was to be one of the most important maps available to Meriwether Lewis and William Clark in planning and executing their famous expedition up the Missouri River in 1804.

Evans's map shows his route up the Missouri River from Fort Charles, located in what is now northeastern Nebraska near modern Sioux City, Iowa, to the Mandan and Hidatsa villages at the mouth of the Knife River in present-day North Dakota. The map illustrates in detail the major features of the Missouri River channel and shows all of its principal tributaries. It is a landmark of Missouri River cartography. Later mappers relied heavily upon it, as no less than ten secondary English, French, and Spanish maps of the period from 1797 to 1811 bear unmistakable evidence of their dependence on Evans's work.1

The Evans map was especially important to the Lewis and Clark expedition. Clark repeatedly referred to it and verified Evans's earlier observations. Indeed, Evans (whose name Clark variously spelled Evins, Evens, and Ivens) named all of the major tributaries of the Missouri River in the area his map covered. In fact, it -remained for Lewis and Clark to name only a few minor streams below the Mandan and Hidatsa villages. Until they reached those villages they made only "secondary and supplementary" maps of the Missouri River, so precise and detailed was Evans's work. It was a major "road map" of the expedition for no less than seven hundred miles.2


Evans, together with James Mackay, led an expedition up the Missouri River between 1795 and 1797.3 Sponsored by Spain, the party left Saint Louis in August, 1795, accompanied by thirty-three men-a party not much smaller than that of Lewis and Clark nine years later. In November they reached the Omaha Indians and built Fort Charles near their village in what is now Dakota County, located in northeastern Nebraska. Mackay subsequently sent Evans up the Missouri to obtain information on intertribal relations. Evans went as far as the mouth of the White River, which is located in south central South Dakota. Here he was forced to retreat by hostile Dakotas, and he returned to Fort Charles.

In early 1796 Mackay again dispatched Evans upriver, this time with instructions to "discover a passage from the sources of the Missouri to the Pacific Ocean."4 With these impossible orders in hand, Evans ascended the Missouri River with a party of unknown size and succeeded in reaching the Mandan and Hidatsa villages at the mouth of the Knife River, in present North Dakota, on September 23, 1796. He remained near these villages through the following winter.