J. David Rogers'
Grand Canyon Research
Marble Canyon

My first research trip in the Grand Canyon was in June 1978, using the Colorado River as our pathway through the 280-mile length of the gorge.  Here I am leaving our put-in at Lee’s Ferry at Mile 0, with the colorful Echo Cliffs in the background.

This is a view of 10 Mile Rock, a large slab of Coconino Sandstone that juts out of the water 10 miles downstream of Lee’s Ferry.  This is how it appeared on June 19, 1978, when the river was flowing about 12,600 cubic feet per second (cfs).

This is how 10 Mile Rock appeared five years later, on June 22, 1983, when the river was flowing 63,000 cfs.

At Badger Creek Rapid (Mile 7.8) I managed to get my raft stuck at the head of the rapid on the first rock I tried to row pass!  At Soap Creek (Mile 11), shown here, the river drops 16 feet feet and I enjoyed an unmolested run down the center tongue.  My confidence grew with each day’s small successes.

This shows a sheet joint-bound wall arch in the Redwall Limestone a short distance upstream of Redwall Cavern, on the left bank.  Sheet joints can form in any kind of massive rock devoid of intense fracturing or jointing.

Coming up on Redwall Cavern on a flow of 69,000 cfs on June 23, 1983.  At this flow it is easier to imagine how the opening was carved out of the Redwall Limestone at a sharp bend in the channel at Mile 33.

Close-up view of Redwall Cavern at Mile 33. The enormous opening was undercut by the river at a sharp southward bend of the channel.  It is now filled with sand, but in the days before Glen Canyon Dam, it was occasionally scoured out by high flows.  The 1923 USGS Mapping Expedition managed to row into the cave riding a flow of about 20,000 cfs.

Back in 1978 everyone used Buzz Belknap’s river guide, the only one available.  It utilized the 1923 USGS plane table survey maps of the river corridor.  Here I am studying the Belknap river guide at Redwall Cavern.

We spent a late afternoon exploring Nautaloid Canyon (Mile 34.7), a fault-controlled slot canyon.  The intricacies of karstic landscape lie hidden below ground.  The Mississippian age nautaloid fossils are the conical variety, like ice cream cones. Nautaloids evolved their spiral form much later, during the late Mesozoic.

Here is the sketch I made from the photo above, showing the controlling fault, dry falls, springs, and collapsed caverns.

Drawing from my field sketch pad showing the collapsed cavern fill exposed on the northwest wall of Nautaloid Canyon and the dry falls, as I imagined it would be seen from above.

Relaxing at the mouth of the Little Colorado River.  The intense turquoise color comes from dissolved carbonate that emanates from springs a short distance upstream.  After the summer thunderstorms begin in early July, this scene changes to a muddy brown sludge, which taints the entire Colorado downstream of this location.

Questions or comments on this page?
E-mail Dr. J David Rogers at rogersda@umr.edu.