The Colorado River and its tributaries are life to the Southwest. It is the only major water source for Arizona and Nevada, and is a critical component of the water used by California, Colorado, Utah, Wyoming, and Northern Mexico. Any discussions of water allocation and the effects of ongoing climate change on the river are political minefields.
In other places, the river flows through broad, relatively unspectacular valleys. That's what happens in western Colorado. Between Glenwood and Grand Junction, the river flows through exposures of the easily eroded Mancos Shale. It might not be spectacular in the scenery sense, but it makes transportation routes a lot more easy to plan. Interstate 70 and numerous railways follow the river in this area.
forced to flow through yet another spectacular gorge, Glenwood Canyon. Millions of travelers have traversed Glenwood through the years, but not me. The rules we set for ourselves on this trip were to see as many new things as possible, so Glenwood showed up on our vagabonding itinerary despite being famous and heavily traveled. It was quite a sight.
I'm committing one of those odd little sins of geography that Glenwood inhabitants might take umbrage to. I'm going to suggest that Glenwood Canyon reminded me of the Grand Canyon, only with forests. In my defense, let me point out the particular similarity. Because the canyon was forced by erosional and tectonic circumstances to cut through a plateau, it carved deep into the crust, deep enough to expose some of the metamorphic basement rocks that are among the oldest found anywhere in the American Southwest. The gneiss and schist exposed here are 1.7 billion years old. The rocks were beveled by intense erosion and later covered by sedimentary rocks that are around 500 million years old (an unconformity). The higher cliffs are composed of Paleozoic sedimentary rocks. This is the same relationship seen in the deepest part of the Grand Canyon.
|Photo by Mrs. Geotripper