Fossil worm burrows in the Grand Canyon, somewhere between mile 220-260 miles below Lee's Ferry.?The traces are identical to those found atop the White Mountains in California, many mountain ranges and hundreds of miles away.? Probably of Cambrian Tonto age, 570-500 m.y.a.). Something about the passing of a worm through wet sand causes a differentiation with the surrounding sand, preserved in the fossilization process. As the Colorado River descends from an elevation of about 3100 feet at Lee's