Not to be Confused with Iowa

One of the most common things I hear guests say on our river trips is, “I never thought Idaho would look like this.”  I don’t know if its because ’Idaho’ sounds a little like ‘Iowa,’ but they seem to think Idaho will have soft, rolling hills and wide open plains. Well, it does have those things in its valleys – 25 billion potatoes need somewhere to grow – but there is much more that meets the eye traveling across the state.

Idaho means, ‘the sun comes down from the mountains,’ originating from the Shoshone Indian phrase ‘Ee’ (coming down), ‘Dah’ sun/mountain, ‘How’ (acts as an exclamation point in the Shoshone language).  If you have spent a fortunate evening sitting riverside on a beach, watching the sun sink down over the dark rocky cliffs, or sipping a cup of coffee on that same beach in the morning as golden light brightens the mountainside, you understand what the Shoshone were trying to capture.

Idaho has over 3,000 river miles, more than any other state in the country.  It is also the 13th largest state in geographic area, but 39th in population.  Idaho contains Hells Canyon along the Snake River, which is the deepest gorge in America surging at a depth of 7,900 feet – 1,000 feet deeper than the Grand Canyon.  It also has the second deepest canyon – known as Impassable Canyon on the Middle Fork Salmon River.  With the Frank Church Wilderness, the most remote area in the lower 48, Idaho offers a true getaway from everyday life.

Now I am not a geologist, or even one of the better river guides at explaining the complicated formation of our great state’s topography.  However, I will attempt to present my first grade reading level explanation of how Idaho’s current landscape was formed.

Hundreds of millions of years ago, Idaho was actually resting on the western coast of the North American tectonic plate. As the oceanic Pacific plate collided with it, the heavier oceanic plate was crushed under the North American plate.  The subducting ocean plate plunged deeper into the earth’s core – becoming hot and molten.  As the rock melted it was pushed upwards, sometimes breaking through the earth’s crust in volcanoes, sometimes remaining just below the surface and cooling into new metamorphic rock.

At the same time the ocean plate was subducting, a chain of volcanic islands had migrated from the equator via other plate tectonic shifts and began shearing off the ocean plate and into the North American coastal plate.  As the North American plate continued to expand, new coastline arose and incorporated these islands, creating what we know today as Oregon and Washington.  There is now evidence of these tropical islands – exotic terrain – in corral reef fossils found in the Hell’s Canyon area and various other places around the Pacific Northwest.  The deeper hot spots of these islands continuingly traveled with the subducted oceanic plate further under the Pacific plate to create new volcanic areas such as: Mount St. Helens and the dynamic heat elements of Yellowstone.

Our river corridors contain many of these rudiments, varying from craggy, dramatic rock outcrops, to unique stair steps and geographic patterns of columnar basalt, to rolling terraces created by ancient glaciers and floods.  There are many beautiful and different environments along all of the rivers that O.A.R.S. runs – from desert red rock to tropical forests to arctic tundra.  Idaho is unique and worthy in its own, and very much worth seeing, even if you only read geology at the first grade level.

Written by Debbie Hausler