Wow...big river. In the tidal areas, the speed changes. But the river flows approx. 2-3 mph. Depending on the water level.
The Columbia River is over 1200 miles long. Portland to DC is about 2800 miles.
The Stikine River is in north-western British Columbia in Canada and south-eastern Alaska in the United States. It is 379 miles long.
Columbia is the capital city of South Carolina. The Saluda River and the Broad River merge at Columbia to form the Congaree River. The Santee River is 25 miles southeast of Columbia.
The Pend Oreille River joins the Columbia about 2 miles north of the U.S.-Canada border and the Columbia enters eastern Washington.
The Hodzana River, Hogatza River, Holitna River and Huslia River are rivers in Alaska.
The Columbia River forms a major part of the border between the states of Oregon and Washington.
The river Thames is 215 miles long, the longest is the river Severn at 220 miles long.
The Orinoco River is 1,330 miles long
The Missouri River is 2,341 miles long and is the longest tributary to the Mississippi River.
The Hudson river is about 315 miles long
Columbia river
The Chattahoochee River is 430 miles long. The river starts in the Blue Ridge Mountains and empties into the Apalachicola River in Florida.