|Willamette Falls after 3 days of solid rain|
But the Flood of '96 was itself dwarfed by the Great Flood of 1861. The Great Flood completely drowned some townships, including Champoeg, the site of the first organized government of the Oregon Territory. The Great Flood was so massive that, at its peak, the volume of water flowing in the Willamette River surpassed that of the Mississippi River itself. The Great Flood is the biggest Willamette River flood in recorded history.
The first Oregonians, the Chinook, the Clackamas, the Long Tom, the Yamhill, who bequeathed their names to the Willamette's tributaries, came here some ten thousand years ago. In those days, before recorded history the Willamette still flooded, but there were backwaters and sloughs to absorb the floods so they wreaked less destruction on the valley floor. The floods were less severe in those days before civilization channeled and deepened the river.
But a few thousand years before mankind first came to Oregon were the great floods. These were the floods that came from the north and east. They were caused by the melt of retreating glaciers. The first and greatest was the Lake Missoula Flood which came when a glacial dam broke open and unleashed an entire ocean of water through the Columbia Gorge, scouring the earth. Over the next few thousands of years, scores of floods literally scrubbed eastern Washington of its topsoil and deposited it in the Willamette Valley. The land still bears the scars of those great washings.
Clear demonstration of two truths, I suppose: the Willamette River is a flood-prone river. And recorded history really isn't much time at all.
I'll tell you this, though: the water made an impressive sight. Roaring and rioting over Willamette Falls.