Not so hasty

  Rivers can be incredibly strong things. During savage flooding they can carry cars, houses, and/or large boulders, down stream. While most of the time the Columbia is not roaring hard enough to do that, it is carrying much smaller objects down stream all the time. The once wild and free flowing river carried uncounted tons of sediment over millions of years out to the ocean. But the ability of the Columbia to carry even sand and silt is greatly diminished by the wall of the Tualatin Mountins. Despite this, more than two and a half times the water cascading down Niagara Falls pours into the ocean over the Columbia Bar.
  The mouth of the Columbia is a thirty mile long, four mile wide estuary. This relatively straight, east-west body of water looses its salinity when it reaches its first major bend. This is the low point between the Willapa Hills of Washington and the Northern Oregon Coastal Range. Upstream from here, the Columbia heads south for another thirty miles to the confluence of the Willamette River.
  It's this second bend of the river that takes all of the steam out of the Columbia's energetic rush to the sea. Having just literally plowed through the Cascade Range to form the Columbia River Gorge, it finds an obstacle it cannot so easily tackle. The Tualatin Mountains, or West Hills of Portland, takes the brunt of of the raging river and slows it down. It is upon the last sixty miles of the Columbia's course that it dumps the majority of it's sediments.
  Along this stretch of the river, there are about sixty islands. Although that amounts to one per mile, they are of such varying sizes and groupings that the estuary at the river mouth (half the length of this stretch) is mostly free of them. Once you reach the end of this curve, just before the Willamette joins the race for the sea, is Sauvie Island, the largest in the Columbia. This island is the largest cache of the dust of dissolved hills from thousands of miles away. Sauvie Isand has grown to a size large enough to fill half of the Columbia estuary, or replace the island of Manhattan. It has it's own system of rivers and lakes.
  Seems a delicate thing to me, completely at the mercy of the river. Even this far in, the Columbia is still subject to oceanic tides.Yet a system of dams helps to prevent what would have once been very common flooding. Thanks to past flooding, much like the fertile delta region of the Nile, this island makes for great farm lands. Strangely enough, this island holds one of only two "clothing optional" beaches in Oregon (most beaches are far too cold, even in summer). The other is in the Columbia River Gorge.
  This stretch of the river is highly navigable (assuming you can survive the Columbia Bar). Large, ocean freighters pass through this region to reach the Portland-Vancouver metro area. Nearly half of all US grain shipments pass through this area.
  The Columbia basin, draining about eight and a third percent of the land area of the US, is it's second largest water system. The largest, of course, is the Mississippi. Yet because of this twist in the river causes by coastal mountains, it is denied a proper delta to make it's mark on the worlds imagination, as the Nile or Mississippi deltas do.
  Next time, I'll talk about my stomping grounds in the Tualatin Valley.

Happy hunting,
Brett