Gorge Geology

10,000 Years Later, Ice-Age Floods Getting Their Due

By Dan Richardson, 10-11-06

	Dry Falls, in central Washington, is a quiet reminder of the power of the Ice Age Floods. Rising 400 feet high and more than three miles wide, Dry Falls at its peak was the equivalent of ten Niagara Falls. (Photo by Terry J. Pieper, courtesy byways.org.)

There’s a surging interest in the Ice Age floods (aka Missoula Floods) that rolled down the Columbia River channel thousands of years ago, carving out much of our modern gorge. All sorts of things are washing up in the new tide of interest, including Congressional action and a new Columbia Gorge interest group.

The Ice Age Floods Institute is a group of Missoula Floods devotees with a number of local chapters. The newest chapter is in the Columbia Gorge, with about two dozen people thus far, according to organizer Terry Hurd. (Email: iceagefloods@yahoo.com.)

The group will meet at different sites around the Gorge; its next meeting will be in Stevenson a week from Thursday, on Oct. 19, at the Interpretive Center, starting at 7 p.m.

The November meeting is expected to be in The Dalles.

(The gorge chapter is not official until the IAFA approves its bylaws; but the group has elected some officers, is holding meetings, and has started collecting a chapter library of books and videos on Ice Age floods along the Columbia.)

The gorge IAFI chapter is the sixth of its kind, with others in communities from to Missoula, Mont., to West Linn, Ore. — following the path of the ancient floods that burst from then-Lake Missoula and roared down the Columbia, shaping much of our landscape. Lyle, for instance, is built on a massive gravel bar left over from the floods; there’s a layer of flood-silt up to 30 meters deep in parts of the Hood River Valley; and here and there in the gorge’s basalt landscape are granite boulders washed down in flood-borne icebergs.

The Flood Institute and its chapters sponsor field trips and talks about the floods, and also interpretive efforts, such as the proposed National Parks trail. As of September, both houses of Congress have passed bills to designate an Ice Age Floods National Geologic Route; the two bills differ, however, and lawmakers must meet to resolve them. That may be completed as early as the end of this year.

(The bills are available here. Enter the bill numbers to read them. Those are HR 383 and S 206.)

While the feds consider how to coordinate and tell the story of the ancient floods, the Washington State Parks and Recreation Commission is already preparing interpretive signage for parks in the flood areas, which could include some like Maryhill and Beacon Rock.

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