Monday, May 23, 2011

Geo-Hiking Around the Lees Ferry Area, Arizona

I recently led a small group on a camping and hiking trip to Lees Ferry along the Colorado River in northern Arizona. There are some very nice hikes that captivate the geologist! Here I write about two hikes - one down Cathedral Wash to the Colorado and the other up the Echo (or Vermilion) Cliffs on the Spencer Trail. One hike is narrow; the other has huge vistas.

The hike in Cathedral Wash begins along the Lees Ferry Road and starts out in the Triassic Moenkopi Formation (upper red unit). Here, Ed is standing on top of the Permian Kaibab Limestone (white below) and the contact not only marks a transition in time periods, but between era's too. Below are Paleozoic rocks with Mesozoic rocks above. The gap in time at this unconformity represents about 35 million years.

Burrowing animals left these traces within the Kaibab, part way down the canyon.

The route is quite narrow in places with beautiful refracted light bouncing off of the limestone walls. In a few places, hikers must negotiate some steep cliff descents that require route finding. It is not for beginning hikers.

But you really cannot get lost -just follow the bed downstream until you reach....

..... the Colorado River.

After a night in the campground, we got an early start on the Spencer Trail. This steep trail cannot be seen from the famous ferry site and raft launching area, yet it climbs the cliffs above. In no time the big vistas begin to appear. This is a view to the south where shale in the Petrified Forest Member is being eroded off the top of the Shinarump Conglomerate Member (both the Triassic Chinle Formation). The Moenkopi Formation is along the river bank. This same couplet can be seen in the low bench in the right distance at the base of the Vermilion Cliffs.

Our group ascending the trail in the cool shade of morning. Behind is the Colorado River in its last reach in Glen Canyon. The dam is located about 13 miles upstream from this point. Note the obvious dip in the Mesozoic rocks in the far background - these are tilted along the Echo Cliffs monocline as it crosses the river.

Higher still, the views become quite expansive. The Vermilion Cliffs are seen in the right background with the Echo Peaks on the left skyline. The colorful Chinle Formation is located in the center of the picture. A large detrital fan from the Paria River has pushed the Colorado into its left bank where it has scoured a cliff in the Moenkopi Formation. This is where Mormon pioneers built the road to connect to the ferry site. This old road is known as Lees Backbone.

The Vermilion Cliffs are one the Southwest's greatest landforms and they attain noble proportions in the Lees Ferry area. The light colored rocks next to the river belong to the Permian Kaibab Limestone, the rock unit that makes up the rim of Grand Canyon. These are overlain by the red Moenkopi Formation and the Shinarump bench in the center of the photo. The soft Chinle Formation has eroded back from this bench and forms a prominent terrace beneath the upper cliff, which contains the Moenave, Kayenta, and Navajo formations. This is geology paradise with a large river in an arid environment providing the scenery and geologic history.

The top of the Spencer Trail was achieved in under 90 minutes and the views were terrific.

Standing atop the Navajo Sandstone (foreground) the Lees Ferry area is popular with river runners, trout fishermen, campers, hikers, even fruit pickers.


A large falling dune is seen on the leeward side of the Echo Peaks. These features form when wind carries sand but drops its load as the wind falls behind a rock obstruction such as a cliff. As the velocity of the wind lessens behind the obstacle, its capacity to carry the sand diminishes and the sand falls to the ground. This is an especially large falling dune.
Note the tilt on the Echo Cliffs monocline as well.

On the way down we noticed some well-developed mud cracks in a block of the Moenave Formation. You may also notice the ripple marks that formed in the dark colored mud before it was dried out.

History and geology share center stage at Lees Ferry and here are some of the remains from a gold mining operation that was located here in the early 20th century. The Spencer Trail is located on the cliff in the background.

I will be leading a 7-day river trip down the Colorado River this August and have a few spots left open. If you would like to see Lees Ferry and enjoy a trip kin the Colorado River through Grand Canyon with a geologists, please contact me!

2 comments:

Emma Springfield said...

I really liked the pictures that dwarf the humans. It is amazing how mammoth these formations are.

AZnativeDeby said...

Thanks for the beautiful photographs and the informative descriptions. I am going to Lees Ferry next week for a few days and look forward to seeing the sights.