25/02/2026
The Columbia River is the largest river in the Pacific Northwest region of North America and one of the most significant waterways on the continent. It originates in the Rocky Mountains of southeastern British Columbia, Canada, at Columbia Lake, and flows northwest before turning south into the United States. The river then travels through the state of Washington, forms much of the border between Washington and Oregon, and ultimately empties into the Pacific Ocean near Astoria, Oregon. In total, the Columbia River stretches about 1,243 miles (2,000 kilometers).
The river’s drainage basin covers approximately 258,000 square miles (about 670,000 square kilometers), making it the fourth-largest river basin in the United States. Major tributaries include the Snake River, Willamette River, Kootenay River, and Deschutes River. The Snake River, in particular, is the Columbia’s largest tributary and contributes a substantial portion of its flow. The basin encompasses diverse landscapes, including mountain ranges, forests, plateaus, and arid regions, supporting a wide variety of ecosystems.
The Columbia River has played a central role in the history and development of the Pacific Northwest.
For thousands of years, Indigenous peoples relied on the river for fishing, transportation, and trade, especially for salmon, which remain culturally and economically important. In the late 18th and early 19th centuries, European and American explorers navigated the river, and it became a crucial route for the fur trade and westward expansion. The Lewis and Clark Expedition reached the Columbia in 1805 and followed it to the Pacific Ocean.
Today, the Columbia River is heavily developed for hydroelectric power, irrigation, flood control, and navigation. Numerous dams, including Grand Coulee Dam and Bonneville Dam, generate a significant portion of the Pacific Northwest’s electricity. These dams have enabled large-scale irrigation projects that support agriculture in otherwise dry regions, particularly in central Washington. The river is also an important shipping corridor, allowing ocean-going vessels to reach inland ports such as Portland, Oregon.
Despite its economic importance, the Columbia River faces environmental challenges. The construction of dams has significantly altered natural river flows and has impacted salmon migration and spawning. Efforts have been made to restore fish populations and improve habitat conditions through fish ladders, hatcheries, and habitat restoration projects. The river remains vital to the region’s identity, economy, and natural heritage, serving as both a powerful natural force and a cornerstone of life in the Pacific Northwest.