Thursday, April 26, 2012

April 23, 2012. The Hawthornes Are At Colorado National Monument. Part 1 Of 3.

Colorado National Monument preserves one of the great landscapes of the American West.  Big, bold, and brilliantly colored, this plateau and canyon country with towering masses of sculpted rock, covers 32 square miles of rugged terrain.  Rim Rock Drive offers 23 miles of breathtaking views.  The road climbs from the Grand Valley of the Colorado River to the park's high country,  then winds along the plateau rim. The highest point on Rim Rock Drive is 6640 feet.
The grand scale of the scenery is overwhelming.

A man named John Otto, the embodiment of the pioneer spirit of the West, waged a single-handed battle to set aside this area for the benefit of the entire nation. Otto arrived in Western Colorado to work on the nearby Fruita pipeline.  When he saw the rugged redrock canyons south of Grand Junction, it was love at first sight.  In 1907, Otto wrote, "I came here last year and found these canyons, and they feel like the heart of the world to me.  I'm going to stay and promote this place, because it should be a national park."  Otto loved the land so much that he campaigned tirelessly for it to be set aside as a national park for future generations to enjoy, experience, and appreciate the sublime geography of this area. And he did so at a time when the national park idea was just coming into focus.  Yosemite, Yellowstone, and Mount Ranier were already established as federally protected lands, but there was as yet no national park service to manage them with any consistent philosophy.  Urged by Otto, the citizens of Grand Junction deluged politicians in Washington, D.C., with letters and petitions in support of the proposal. In the meantime, Otto built miles of tortuous trails through the proposed park area so others could appreciate its beauty.  He did all of this without any hope of personal gain.  In 1911, Otto's dream came true:  Colorado National Monument was established.  Otto was rewarded by being named the park's custodian,
 a job he gladly held until 1927, for $1 a month.

 Colorado National Monument is amazing.
I only took about 300 pics, so I'm dividing 
into 3 different posts.

Please enjoy!

Mr. Hawthorne and I got out to take a little walk here. 

Spectacular views.

With about 20 switchbacks, this old road was once called the "crookedest road in the world."  In 1961, the Serpents Trail was converted to a hiking trail. In 1912, construction began on the Serpents Trail, which was the first motorized route across Colorado National Monument.  John Otto, the park's first custodian, suggested the route for the road and residents of nearby Glade Park and Grand Junction raised funds for its construction.  The original route had over 50 switchbacks.  When it was completed in 1921, most cars lacked fuel pumps and had to back up the steep road so that fuel flowed to the engine by gravity.  By 1950, construction on the east hill of Rim Rock Drive was completed and the Serpents Trail was closed to motorized traffic.  Now a hiking trail, the scenic path curves back and forth through Wingate Sandstone for 1.75 miles losing 770 feet of elevation along the way.

Around 70-40 million years ago, The Redlands Fault lifted the layered sedimentary and metamorphic rocks of the Monument above the Grand Valley.  Since then, erosion has carved magnificent steep-walled, flat-bottomed canyons that literally hang above the Colorado River.

The Monument's canyons are still evolving as erosional processes deliver sediment to the Grand Valley.  For at least the last 5 million years, sand and silt and mud washed from the Monument have headed southwest toward the Gulf of California via the Colorado River.

Humans have occupied this canyon landscape for 12,000 years,
leaving behind tools, shelters, and rock art.

While this might look like a glacial U-shaped valley, it isn't.
It's a canyon formed by flowing water.
Notice how the the profile of this canyon
"frames" the city of Grand Junction in the distance.
The unobstructed view reflects a dramatic drop in elevation
between my viewpoint and the city below.
While the Colorado River "quickly"
(in geological years) eroded the Mancos Shale in the valley,
tributary streams in the canyons
eroded harder rock more slowly.
The difference in elevation
between the Grand Valley and the Monument's canyons grew,
leaving "hanging canyons" such as this one.

Once the canyon's stream carved through the softer sedimentary layers 
of the Kayenta, Wingate, and Chinle Formations,
 it reached the hard basement rock of the of the canyon floor.
  Downward erosion almost stopped 
while horizontal erosion continued. 
 At the far end of the canyon, 
where the valley floor dips downward and the stream flows faster,
 a prominent notch was eventually carved.
 Rockfall from adjacent cliffs and 
sand and gravel from upstream currently cover much of the valley floor.

Although flowing water is the force that carved these canyons,
the shape and direction of the canyons were
influenced by the rocks themselves.

Folding and faulting formed planes of weakness and cracking
in several consistent directions.
Flowing water subsequently eroded the rocks
along these consistent lines of weakness,
leaving long, straight canyons.

Summer rainstorms can cause massive flooding.
As floodwaters move boulders and cobbles downstream,
the tumbling rocks wear away underlying bedrock,
helping to carve the canyons.
Thunderstorms here are violent,
but usually short-lived.

As floodwaters subside, lessening flows can no longer
carry heavy boulders and cobbles,
leaving them behind on the canyon floor.
Further along, as water velocity continues to slow,
pebbles, sand, and silt also settle out.
Flood deposits show this grading,
as large to fine-sized particles settle out sequentially.
Geologists recognize these deposits
 in all the canyons of the Monument.

Stay tuned for Part 2 of 3 of the Colorado National Monument.


Marilyn said...

Interesting and lovely. Just don't ask me to identify any of the plants!

Rosie Hawthorne said...

But Mar, you're my personal Master Gardener! BTW, the red one is a desert paintbrush plant.