UNAWEEP CANYON, looking southwest from rim of inner gorge cut in hard Proterozoic rocks, just to the right side of first cattle guard on Divide Road, near middle of sec. 16, T. 14S., R. 100 W., about 5 miles northeast of drainage divide shown in [figure 34]D. Drainage divide is just around the corner to the right of the most distant part of the canyon visible. Slope above vertical cliff on right consists of Chinle Formation, Wingate Sandstone, and flat crest of Entrada Sandstone (Kayenta Formation is absent). Paved road in canyon is Colorado Highway 141. (Fig. 36)
A Look into the Future
This ends the brief geologic story of Colorado National Monument, except for a peek into the future, a description of trips through and around the Monument, and a comparison with other Parks and Monuments on the Plateau. The temporary nature of lakes, rivers, and even mountains has been discussed—the Monument of today and the new course of the Colorado River are no exceptions.
The Colorado River did not solve its problems by abandoning its hard-rock course in Unaweep Canyon in favor of a soft-rock course through Ruby and Westwater Canyons—it just postponed them. The river has again cut down into its old nemesis—the hard Proterozoic rock—in Ruby Canyon just within the Colorado border, in Westwater Canyon in Utah, and the Gunnison River has reached the hard rock at its confluence with Dominguez Creek, not far above Whitewater, as shown in [figure 34]D. Thus, once again hard rock is slowing down old man river, and will slow him down for a long time to come. Someday, Westwater and Ruby Canyons will be deep gorges like Unaweep Canyon. Then it is quite possible that another young tributary may sneak around the Uncompahgre arch some miles northwest of these canyons and pirate the river into a new soft-rock course.
By this time, the Monument will have changed appearance considerably. Some of the canyons will have come together by eating away the ramparts that separated them—just as the two entrances of Monument Canyon have already done. But as the lower canyons thus eliminate themselves, the headwaters will bite deeper into Piñon Mesa, so perhaps the Monument will simply creep slowly southwestward. However, renewed uplift, more volcanos, changes in climate, or other events could alter the picture.
Still, if the geologic clock ran as fast as the ones we use, the picture of the Monument we see today would be on the screen only a small fraction of a split second. But the geologic clock ticks on, slowly but surely, and, someday, the Holocene Epoch in which we live will become just another brief chapter in the long geologic history of the Earth.
