The river that flows underneath the Columbia River?

Question

When I worked at an answering service, one lady who worked there said her grandfather had once worked with the Corps of Engineers.

That when they were drilling underneath the ground where Bonneville Dam is now located, the Corps discovered an underground river. She said her grandfather spoke often about this. She said he said the river was found to be wider than the Columbia River and the depth was unknown.

Has anyone any supporting information?

Thanks

Answer 1

Howard H - the course of the Columbia was in existence PRIOR to the Missoula flood events. The floods came down the existing river channel (after scouring across eastern Washington).

Answer 2

Underground rivers are VERY VERY rare. You may seen one in caves where the open space facilitates the flow of underground water out of the wall at a particular point, but almost always the water in the ground is in a layer, not in a stream. BTW, this is one reason dowsing is bogus.

The Columbia river bed was scoured deep by catastrophic floods from glacial Lake Missoula, and you can research this on-line. Many of the spectacular water falls along the south side of the Columbia are from hanging streams that were left high on the wall of a newly rapidly eroded river bed.