This brings us to the remarkable transformation of the original V-shape of Unaweep Canyon to the beautiful U-shape of the present canyon, which is shown in figure 36. The abandonment of Unaweep Canyon discussed earlier removed the gigantic storm sewer that for millions of years carried off the products of vigorous erosion of the canyon walls by the processes just described. Rock materials that now fall from the cliffs of the inner gorge in hard Proterozoic rocks and that fall from the overlying softer sedimentary rocks simply pile up at the foot of the cliffs to form a canyon equally as U-shaped as those cut by glaciers in the high mountains. Indeed, Unaweep Canyon has been mistaken for a glacial canyon by many, including some geologists. [Illustration: Petroglyph] [Illustration: FALLEN ROCK, in west arm of Ute Canyon below waterfall, from Fallen Rock Overlook. Note that the sun-facing left side of canyon, containing the fallen block of Wingate Sandstone, is a vertical cliff; whereas, the shaded right side can be readily climbed. The right side contains a trail near the middle of the picture, but it is hidden by vegetation. (Fig. 35)] [Illustration: 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.