^The Rivers, Balance of Power: Hydroelectric Development in Southeastern British Columbia; Touchstones Nelson: Museum of Art and History. Retrieved on 2008-09-16.
^"Water-data report 2007: USGS 14243000 Cowlitz River at Castle Rock, WA"(PDF). United States Geological Survey. 2007. Retrieved 2008-10-24. Discharge data taken from a USGS gauge 14243000 at Castle Rock, 17.3 miles (27.8 km) from the mouth, measuring the flow from about 2,238 square miles (5,800 km2) or 85 percent of the total watershed.
^Calculated by summing subbasin sizes listed in Lower Columbia Tributaries, Northwest Power and Conservation Council; and Toutle Management Plan, Northwest Power and Conservation Council. Retrieved on 2008-09-16.
^Lower Columbia Fish Recovery Board (December 2004). "Volume II – Subbasin Plan Chapter G – NF and EF Lewis"(PDF). Lower Columbia Salmon Recovery and Fish & Wildlife Subbasin Plan. Northwest Power and Conservation Council. Retrieved 2008-10-14.{{cite web}}: CS1 maint: date and year (link)
^Loy, William G. (2001). Atlas of Oregon. Eugene, Ore.: University of Oregon Press. pp. 164–65. ISBN0-87114-101-9. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
^"Wenatchee River Basin: 12459000 Wenatchee River at Peshastin, WA"(PDF). United States Geological Survey. Retrieved 2008-10-16.. Discharge data taken from USGS gauge 12459000 at Peshastin, 21.5 miles (34.6 km) from the mouth, measuring the the flow from about 1,000 square miles (2,600 km2) or 77 percent of the total watershed.
^Water Data Report WA-05-1, chapter Okanagan River Basin. Retrieved on 2007-04-20. Discharge data taken at Malott, Washington, 17 miles (27 km) from the mouth, measuring the flow from about 8,080 square miles (20,900 km2), about 97 percent of the total watershed.
^"Water-Data Report 2007: 12404500 Kettle River near Laurier, WA"(PDF). United States Geological Survey. 2007. Retrieved 2008-10-18. Discharge data taken from a USGS gauge near Laurier, 29.71 miles (47.81 km) from the mouth, measuring the flow from about 3,800 square miles (9,800 km2), about 90 percent of the total watershed.
^"Water-Data Report 2007: 14048000 John Day River at McDonald Ferry, OR"(PDF). United States Geological Survey. 2007. Retrieved 2008-10-19. Discharge data from a USGS gauge at McDonald Ferry, 20.9 miles (33.6 km) from the mouth, measuring the flow from about 7,580 square miles (19,600 km2), about 95 percent of the total watershed.