Sculpted by a never ending combination of plate tectonic motion and erosion, the wonderful and dynamic crust of planet Earth presents us with awe-inspiring landscapes. Tectonic plates scrape past one another, diverge, and crash together, and the rocky crust of our planet is torn, exhumed, deformed, and uplifted. As magmatism and volcanism contribute new crust to the Earth system, streams and rivers work to strip the land of its crust. This is all a part of the beautiful, never-ending rock cycle.
The mighty Rocky Mountains of the western United States rise dramatically from valley floors into the low levels of the atmosphere as a result of the tectonic and erosional processes described above. They represent the culmination of approximately 100 million years of tectonic plate convergence, during which time vast thicknesses of rock pile atop one another, much like the snow at the end of your shovel when clearing your driveway. When the contractional stress was removed, the crust of western North America relaxed and extended. Erosion became the dominant sculptor of the landscape, a role it continues to fill today. The Great Divide represents the crest of this impressive mountain range and serves as the hydrological boundary that determines where eroded material gets transported. Also known as the Continental Divide, this line separates the watersheds that drain into the Pacific Ocean from those that drain into the Atlantic Ocean (and to the north, the Arctic Ocean). It is a particularly impressive hydrological division because of the high elevation and line of prominent peaks that it traces. It is also important to mention (considering the circumstances) that the Great Divide runs between the cities of Bozeman and Missoula, serving as a geographical barrier between Bobcat and Grizzly country (institutionally speaking). The appropriately named “Great Divide Trophy” is awarded to the winner of the UM vs. MSU football game each year as we come together in an intense but friendly rivalry.
As we arrive at this point in the year once again, let us acknowledge that the trophy we pass back and forth is named after a geologic feature made manifest by tectonic powers far greater than our own. Let us be humbled by the staggering forces and great antiquity of the planet we inhabit whilst recognizing that the barriers between us are surmountable and that, in the end, we are all on the same team.