July 14, 1811: English-Canadian explorer David Thompson arrives at Fort Astoria

Map of the Columbia River watershed with the Columbia River highlighted

English-Canadian explorer David Thompson, representing the North West Company, navigated the entire length of the Columbia River from its source in Canada to the Pacific Ocean, arriving at the partially constructed Fort Astoria on July 14, 1811. He was the first European to travel the entire length of the Columbia.

Between 1784 and 1850, Thompson traveled more than 55,000 miles while exploring and mapping nearly 2 million square miles of North America.

The North American Exploration David Thompson Bicentennials were celebrated in 2011 to recognize the accomplishments of possibly the greatest land geographer of all time:

Thompson’s accomplishments helped define North America both geographically and imaginatively. His achievements include the surveying in many of the townships of Ontario and Quebec; the determination of large sections of the boundary between Canada and the United States; the establishment of the Columbia basin fur trade; exploration and mapping of a vast area of western North America and the documentation of the nature, history and culture of much of the continent.

Columbia River map with watershed highlighted was created by Wikimedia Commons user Kmusser, and is used here under the Creative Commons Attribution-Share Alike 3.0 Unported license.