1 River Valley Size

• Mississipi River basin 2,980,000 km2 (Gulf of Mexico)
• MacKensize River basin 1,805,200 km2 (Arctic Ocean)
• Lawrence River basin 1,344,200 km2 (Eastern Canada)
• Nelson River basin 1,072,300 km2 (Hudson Bay)
• Yukon River 833,232 km2 (Alaska)
• Columbia River 670,000 km2 (Pacific NW)
• Colorado River 640,000 km2 (Pacific Mexico)
• Rio Grande 472,000 km2 (Gulf of Mexico)
• Churchill River 281,300 km2 (Hudson Bay)
• Fraser River 220,000 km2 (Vancouver, BC)
• Susquehanna River 71,000 km2 (Atlantic)
• Sacramento River 69,000 km2 (California)
• Klamath River 40,630 km2 (Oregon)
• Hudson River 36,000 km2 (New York)