Before embarking on our trip to the Four Corners region of the United States, the first task I assigned the participating students was to define the Colorado Plateau. I didn’t set many parameters. I was expecting the responses to could include information on the following: size, ecology, geology, and culture. My motive for the assignment was multifold. First I am an earth science educator and I wanted them to learn the classic definition of this landform.Â
Geologically speaking, a plateau, also called a tableland (describing the characteristic shape), is a highland area, usually consisting of relatively flat open country if the uplift was recent in geologic history http://en.wikipedia.org/wiki/Plateau. Plateaus are like the progressively smaller features- mesas and buttes. They all are formed when land has been uplifted by tectonic activity and then eroded by wind and water. Often the flat-topped, sheer-sided plateaus, are formed when the section of land that is uplifted is topped with a layer of particularly resistant, volcanic like rock, and underlain by softer rock.
Given the above definition, one would half-expect to be able to drive around the perimeter of the Colorado Plateau, and look down at the surrounding landscape below. This is definitely not the case. I wanted the students to then learn the same lesson I had, the Colorado Plateau isn’t one really large, raised, layercake like formation that sits above the surrounding land. It contains many other smaller plateaus, mesas and buttes and, in fact, it is surrounded by higher bordering mountains.
In reading the students responses I thought more deeply about the value in defining this physiogeographic region. Not one student had written about the elevation of the Colorado Plateau. The Colorado Plateau is not of uniform elevation partly because it has been dissected by the Colorado River and its tributaries. Therefore, the elevation varies from 2000 feet to approximately 13,000 feet, with a wide variety of flora and fauna, but mostly it is a high desert (Colorado Plateau And Its Borderlands, 2004 time Traveler Maps, 2nd ed., www.mapZ.com.)Â
I now wonder after having visited the Colorado Plateau, to what degree the students recognize that the area is one of the least populated regions of the United States. And why is this so? Is it the dryness and lack of water? Humans are known for engineereing solutions around this shortfall, and for the well researched story of the Bureau of Land Management and its dams in this region, one only has to read Cadillac Desert: The American WEst and Its Disappearing Water by Mark Risner, 1993.). Maybe the sparse population is due more to the lack of private land. The region “hosts the greatest and most diverse collection of national parks and public lands on earth!” ((Colorado Plateau And Its Borderlands, 2004 time Traveler Maps, 2nd ed., www.mapZ.com.) Given that so much of the land is federally owned or reservation land of one tribe or another, development is very limited in particular regions.
Of the various maps of the Colorado Plateau region I’ve studied, I’m always looking at the consistency of boundaries, scanning for topographic features which will show elevations and presence of vegetation, and noticing new, smaller features contained within the region. I’ve also wondered what the region looks like from space, from satellite images. This led me to the first five images and maps at the following site: http://rst.gsfc.nasa.gov/Sect6/Sect6_7.html, which point out that the Colorado Plateau is recognizable in satellite images which use color-coding to show sparsely vegetated areas and contrasting surrounding regions which border it- the Southern Rocky Mountains to the east, the Basin and Range to the West, and the Central Rocky Mountains to the north. I use to live on the edge of the Mogollon Rim, south of Flagstaff, Arizona and the San Francisco Peaks, which in fact is a large escarpment dropping off to the lower Sonoran desert region in southern Arizona.  A second true to color satellite image is found at the top of the page at http://www.cliffshade.com/colorado/colorado%5Fmon/. The salmon pink color clearly marks the Colorado Plateau from the dark green forests and white snows that border it. –Mary Ann McGarry, instructor
