This latter chasm begins near the mouth of the Little Colorado River and extends southwest 217 miles. The granite gorge section is sixty-five miles long. Here the plateau level varies from to feet above the sea. The river has carved a winding channel through the uplift more than a mile deep and from ten to thirteen miles wide. In-this titanic trough are hundreds of mountains more imposing than Mount Washington, yet none of which project their peaks above the canyon's rim. The ages-old rock strata are many tinted, creating a rainbow sea of color. There are safe trails at three points on the southern side from rim to river.