Lake What-a-huge-e?

Dr. Crystal Science says (I only have a masters degree in science…) in ancient times a small lake existed in the Grand Canyon. I call it Lake What-a-huge-e (the name and possibly the whole story came to me in a dream). This lake extended from Fossil Rapid to Blacktail Canyon and possibly beyond. Imagine…a lake, its clear waters lapping on a shoreline of cottonwoods and reeds in the heart of Grand Canyon. Imagine too a bronzed native man, muscles bulging, paddling his cottonwood canoe towards a sexy native woman dressed in a primrose bikini, bathing on a woven yucca matt. Whoa! Dr. Crystal Science believes this lake surely was a hot spot for locals.
Lake What-a-huge-e tells us an interesting story in Grand Canyon geology. Evidence shows a remnant damsite, lake deposits, out of place river gravels, a nonrusted dolomite band, and a yucca matt. With this abundant evidence, Dr. Crystal Science believes Lake What-a-huge-e formed in the not so distant past.
Today’s riverrunners can see Lake What-a-huge-e’s remnants. The damsite is the primary evidence of the prehistoric lake. Its location is approximately one quarter mile above Fossil Canyon and consists of a pile of broken up rocks (see Figure 1, river right). This rock pile is approximately 300 to 400 yards long and eighty feet high. Upon closer inspection, one might notice the rock pile is mostly made up of the Redwall Limestone. Knowing this, one can look up in the Redwall to a source. Sure enough, just overhead on the opposite side of the river is a rather huge slide area which is bordered by the Butchart Fault.

This is easily visible from about 200 yards upstream of Fossil rapid (see Figure 2, looking upstream). More evidence comes from the Dolomite Band in the Bright Angel Shale. Normally this layer takes on a very distinctive red color, but at the damsite, the layer isn’t rusted, which means the rock probably was buried by the dam and exposed recently (see Figure 3).
One might ask where are the lake deposits? Curiously, upstream from this remnant damsite are rather large sand dunes (see Figure 4). These dunes could easily represent an ancient lake.
Another interesting clue is the pile of river gravels which exist upstream of Forster Canyon on river right (see Figure 5). These gravels might play a part in Lake What-a-huge-e. Dr. Crystal Science believes that there is substantial evidence to claim Lake What-a-huge-e’s existence.
In short, I have either discovered or made up an amazing geologic event in Grand Canyon. An earthquake occurring on the Butchart Fault precipitating a landslide, the formation of a dam and Lake What-a-huge-e (see Figure 6). Then as the Colorado River filled the lake and overflowed the dam, erosion took over to the point of no more Lake What-a-huge-e. That’s all for now folks.
Look around. Check it out on your next trip.

Dr. Crystal Science
(aka Jon Hirsh)