In 1739 the brothers Pierre and Paul Mallet, earliest explorers along this river's lower course, named it after the French word for flat. Although the sighting tube aims at a wide, strong-flowing current, the North Platte is not navigable.It is unlikely that prehistoric foragers, habituated to arid environs, would have attempted a journey on water. But flint quarries and hematite miners, accustomed to cruising Midwestern rivers and burdened with the products of their labors, might have tried the Platte. In 1812 Robert Stuart's party of eastbound Astorians, recorded discoverers of this ancient, transmontane route of aborigines, wintered a short distance downstream. They fashioned dugout canoes and embarked on the spring floods of 1813, but their craft soon stranded on sandbars and they finished their journey on foot. Eleven years later Tom Fitzpatrick and other trappers again put a boat in the Platte. They encountered wild waters between canyon walls and, though experienced voyageurs, lost a part of Ashley's valuable furs. There after, mountain men stuck to their horses.The Platte's chief historical significance, other than as a natural route for transcontinental travel and commerce, relates to the "arid-lands culture theory" of John Wesley Powell, 19th century explorer, ethnologist, engineer and statesman. An agency created through his instigation, the U.S. Bureau of Reclamation, constructed along the Platte one of the west's first great irrigation systems. The prosperity resulting from the regulated spreading of North Platte waters over formerly arid lands is visible for hundreds of miles along the river's course.