Natural History & Ecology

GEOLOGY

A whole lot of upheaval occurred to create the Columbia River Gorge and in turn the terrain found in the Mark O. Hatfield wilderness area. Far from an expert on tectonic plates and volcanos my understanding of

what happened goes something like this:

When Pangea rifted from the moving tectonic plates North America was pushed away from Europe and Africa. It drifted into the Panthalassic Ocean (the ancestor of the Pacific). The Farallon plate eventually subducted on its westward side, creating island arcs (a group of chain of islands with an arc shaped alignment, often of a volcanic nature). This all happened somewhere between 90 to 150 million years ago.

The Columbia basin was under and inland see for many more millions of years until it eventually lifted up and drained of water between 40 and 20 million years ago. Much more recently, a mere 20 to 40 million years ago, a series of violent volcanic eruptions occurred changing everything. 6 to 17 million years ago floods of basalt lava flowed over and covered the Columbia River Plateu. This served to channel the lower Columbia River to the path it flows today. It also created the incredible basalt cliffs and rocks in the Columbia River area, specifically in the Mark O. Hatfield Wilderness. Still, the tumultuous creation of the Columbia River Gorge and Columbia Basin were not complete. At the end of the last ice age, between 13,000 and 19,000 years ago (it seems like yesterday) ice dams that had held Glacial Lake Missoula ruptured. The Missoula Floods were the result. These floods moved with the force of the combined flow of all the rivers in the world combined and they occurred dozens of times over many thousand years. 

FIRE

Naturally occurring fires have not been a big problem in the Mark O. Hatfield Wilderness Area. Man made fires are a different story. Last October a 13 acre fire caused parts of the Eagle Creek trail in the Wahtum lake area to be closed down. According to the Hood River News out of the 75 fires to break out in the Mt. Hood National Forest only 7 of them were caused by lightning (McCarty, 2012). Sadly most of the damage to this place we are trying to protect is coming from humans, largely because they are not following the rules and regulations for using the area. The Forest Service did act to put out this fire as quickly as possible.