Indian Ocean
Columbia river
its true
The two rivers that run westward into the Columbia River are the Willamette River and the Yakima River. The Willamette River flows through Oregon and merges with the Columbia River near Portland, while the Yakima River, originating in Washington, also contributes to the Columbia River system. Both rivers play significant roles in the geography and ecology of the region.
Snake Willamette
Hudson River
Snake Willamette
it is either the missisippi or the missouri
A watershed is not a building, it is an area of land that contributes run off to a given lake, stream, river or other body of water. It's purpose is to supply water to the water body. (From Ask.com)
All streams including rivers run downhill, so melting snow, rain, etc. produce water and this water drains into rivers and the rivers run downhill until they empty into a larger river or a major body of water like a gulf or ocean.
I live in the wonderful state of Oregon, only about 20 miles from the Columbia. It originates in Canada, comes south into Washington and then makes a westward turn to form most of the state line between Washington & Oregon. It is the largest American river to flow into the Pacific and the 4th larges river in the USA. It's BIG & beautiful. Portland, Oregon is about 90 miles inland, but we get ships from the ocean because the river is deep enough to handle them.
Columbia has 3 rivers that run through the city. They are the Saluda, Congaree, and the Broad rivers.