Green scene

Landmarks created with a flood, and maybe even a prayer


I grew up on Bible stories, and Noah and the flood is one of the more dramatic ones.

It has become fashionable to view these stories as allegories or fables, although it also is a great conservation story — catastrophic habitat change, the need for enough breeding pairs and finally repopulation when appropriate ecological conditions are restored.

In any case, as I started reading folktales from around the world, it became clear that most — if not all — had a flood story, which certainly hints at a widespread, massive event. It has niggled in the back of my mind as an unanswered question over the years.

Several years ago, we visited Yellowstone National Park, which offers a glimpse of a gaseous, volcanic primordial world. After a few days, since we were in a part of the country we had never visited before, we checked out several other National Park Service sites.

In addition to the national parks, there also is a series of national monuments. The difference in designation is that a national park represents large areas protected for their scenic inspirational, educational and recreational value, while national monuments contain material of historical, cultural and scientific interest, making them considerably more varied.

National parks are created by acts of Congress, while only a sitting president can designate national monuments by authority of the Antiquities Act of 1906 signed by Theodore Roosevelt. Many national monuments such as Bryce Canyon and Zion have gone on to become national parks.

In any case, knowing that we would be unlikely to return to Idaho, we looked around for other areas to visit. Two within our driving range were Craters of the Moon National Park — which I highly recommend — and Hagerman Fossil Beds, also a national monument.

The first sounded utterly exotic, and the second coincided with my hope to see a working fossil dig. Alas, we were disappointed that the beds were no longer open to the public due to widespread pilfering. However, we were allowed to drive to spots above the canyons, and that’s when things became interesting.

One of the overlooks had signage reporting a massive flood — so huge as to be incomprehensible — which had caused massive erosion of solid rock in a matter of weeks. It claimed that 15,000 years ago, water had flooded out of Lake Bonneville — an inland lake in southeastern Idaho — bursting over its rim at Red Rock Pass, said rim having been created by rocky debris deposited by flowing water.

It discharged approximately 935,000 cubic meters per second of water, which translates into 33 million cubic feet per second, with a water height of 2,500 feet for eight weeks. The flood finally ended when Bonneville Lake’s height had dropped 108 meters.

Great Salt Lake is considered to be a small remnant, with an average of 1,730 square miles of Lake Bonneville, which originally covered 32,000 square miles.

I must admit to great difficulty in conceptualizing this catastrophe. And this flood is considered to be only the second largest flood in recent times. It pales in comparison with the floods from pro-glacial Lake Missoula in western Montana 14,000 years ago.

“Pro-glacial” means that the lake was formed when water from a melting glacier was dammed either by glacial ice or rocky deposits left by glacial movement.

Eastern Washington State has an area of about 1,500 square miles known as the Scablands. An unflattering term, it refers to rocky, elevated terrain that cannot be farmed.

The accepted wisdom in the early 1990s was that these channeled scablands — channeled because it is full of coulees, which are dry riverbeds carved by water — formed slowly over eons.

Enter a colorful geologist named J Harlen Bretz — J without a period. He believed that the cause was violent water of catastrophic proportions, although he was stumped in regards to the water’s source.

Orthodoxy prevailed for many years until Joseph Pardee discovered giant ripple features — some up to 50 feet in height — in the scabland landscape that proved the violent movement of huge quantities of water.

Even so, the landscape could only be torn up so badly because the underlying rock was volcanic basalt, which tends to crack upon cooling. Then, when these enormous torrents were released, the sheer force of great quantities of speeding water just ripped the rocks apart.

In all, there many have been 40 different torrents from Lake Missoula.

There seems to be evidence for several deluges between 7,600 and 16,000 years ago, and others stretching much further back.

There many have been two catastrophic floods — one 225,000 years ago, and the other 425,000 years ago, that created the English Channel.

Who knew?