Science-Nature | Information Bravo

Locale: The Grand Canyon is 277 river miles (446 km) long, up to 18 miles (29 km) wide, and a mile (1.6 km) deep. Despite its being a very well-known natural geologic formation, there isn’t complete consensus among scientists as to how the canyon was formed. As the LiveScience website says,

The specific geologic processes and timing that formed the Grand Canyon spark lively debates by geologists. The general scientific consensus, updated at a 2010 conference, holds that the Colorado River carved the Grand Canyon beginning 5 million to 6 million years ago.

However, recent advances in dating techniques have upended the notion of a uniformly young Grand Canyon. The new approach determines when erosion uncovered rocks in the canyon. The big picture: there were two ancestral canyons, one in the west and one in the east. And the western canyon may be as old as 70 million years.

In a more recent timeframe,

García López de Cárdenas, an explorer from Spain, was the first European known to have viewed the Grand Canyon. As a member of the 1540 expedition of Francisco Vásquez de Coronado, he led a party from Cibola, the Zuñi country of New Mexico, to find a river mentioned by the Hopi. After a 20-day journey he was the first white man to see the Colorado River and the Grand Canyon.

An avid outdoorsman, President Theodore Roosevelt was an enthusiastic admirer of the Canyon, but it would be years before it became our fifteenth national park: in 1919, the Grand Canyon National Park Act was finally signed by President Woodrow Wilson.

Weather: High 100 at Grand Canyon, Low 60. Mostly sunny, afternoon thunderstorm

Creatures: Bighorn sheep (Ovis canadensis), Abert’s squirrel (Sciurus aberti)

Itinerary: Hart Prairie to US 180, to Valle, to Tusayan, to Grand Canyon Village, and return

Excursions: Grand Canyon (Shoshone Point Trail, El Tovar Restaurant, Bright Angel Trail, Kolb Studio)

Guest Speaker: Bob Jensen, former Hart Prairie Caretaker (evening)

Reflections: The Canyon is indeed grand! I stood and stared and tried to take it all in: the depth, the colors, the covert wildlife, the immense span of time represented.

Images: Visit to the Grand Canyon (click on the 3 vertical dots at the top right to select slide show)

Protect, Transform, Inspire: Touching seven US states and two countries, the Colorado River is a poster child for the need for cooperation in natural resource usage and conservation. From its source high in the Rockies, the Colorado River journeys some 1,450 miles to its terminus in the Gulf of California, draining a total of 243,000 square miles. Though we often think of the Colorado River as a key player in the so-called western water wars, in fact, the 1922 Compact has worked remarkably well to mediate conflicts over water rights. Unfortunately, today the River faces an uncertain future, basically because demand for the water is already exceeding its supply. Together with other stakeholders, TNC and partners like the Sonoran Institute are actively working to protect healthy flow regimes where they are currently found, and to restore river flows where they are degraded. The hundred miles of the Colorado River Delta is one example where water has rarely flowed in the past fifty years. To address this issue, hydrologists came up with the concept of a “pulse flow,” or a temporary surge of water that mimics what happens naturally in a free-flowing river. An historic agreement between the United States and Mexico, called Minute 319, allowed water to be released from the Morelos Dam, which over the course of eight weeks in early 2014 slowly made its way to the sea. It’s a wonderful story, but the ending has not been written yet.

Weather: High 87, Low 54. Sunny

Creatures: Nuttal’s Cottontail (Sylvilagus nuttali), Prairie Dog (Cynomys gunnisoni)

Itinerary: FR 151 to FR 418 to FR 562, return by US 89 to US 180

Excursions: Lockett Meadow, Water Line Road

Speakers: Dale Turner, TNC, Restoring the Colorado River Delta (evening)

Reflections: Lockett Meadow Campground is at 8,600 feet; we gained 600 feet when we climbed to the Water Line Road, which is at 9,200 feet. I can believe that aspens (Populus tremuloides) are among the most widely distributed trees in the United States; they reproduce by root-system cloning. They say that in the fall, when the colors change, aspens turn the landscape to gold.

Images: