So I asked my question.
“I was here 50 years ago. How much has the Canyon eroded since I was here last?”
I was standing at the edge of the South Rim of the Grand Canyon in Arizona. I was talking to a park ranger who looked like she would appreciate my curiosity – and also looked like she would know the answer.
She answered, “The Canyon erodes about the thickness of a piece of paper each year.”
“So,” I said, “that’s 50 sheets of paper, a tenth of a ream, about three-quarters of an inch. I thought I saw the difference.”
And yes, I did see a difference. Not when I peer over the edge and look outwards towards where I can see the Colorado River, but when I look around. There are more people at the Canyon then there had been in November of 1973. The Park is more modern. The trails look better than they had 50 years ago. But the trail down into the Canyon looked just as challenging.
In both my visits to the South Rim, 50 years ago and now, there was snow on the ground. The snow adds to the beauty of the Canyon, as the rocks and trees and shadow are accentuated by the stark white of the snow. But caution is necessary as the trails can be icy and slippery. But with snow or sun caution is always necessary as with the added erosion of the past 50 years its a long way down – plus a bit.
During this visit I would not hike the South Kaibab trail; I would do my hiking on the rim trail. But in 1973 I wanted to see how far down I could get before I had to come back up at day’s end. I started early in the morning with a light pack that I bought the day before in which I had an extra pair of gloves, some sardines and crackers, and something to drink. I don’t think they sold water in bottles back then. I was layered against the cold and had on my sea-duty rain jacket with a hood. It was heavy over my denim jacket, but it would certainly keep me dry. I also had on my woolen watch cap.
I had my copper bound walking stick and was ready to begin my descent. It was cold and clear, and I was the only person on the trail. It was great. The views of the Canyon opening to me were exhilarating. I could look back millions of years as I passed the rock face of the trail wall. I took time to think of all the history that had passed in the first few yards, and then I was well down into the prehistory of the Earth.
It was the uplift of the Colorado Plateau that allowed the marvel of the Grand Canyon to become. About 70 million years ago tectonic forces lifted an area that is now within Colorado, Utah, New Mexico, and Arizona. As mountains formed and snows and rains fell the nascent Colorado River began its journey off the Colorado Plateau down to the Gulf of California. The River began to cut its way through the uplifted plateau as it sought to reach sea level. As it picked up sediments from its sources it flowed across the uplifted plateau like liquid sandpaper. The rushing River gouged and polished its way down to its present level. As the River grew so did the feeder streams that flowed into it; each cutting its own side canyon. The Canyon sides collapsed as the River cut deeper. This collapse created the width of the current Canyon. Rain and freezing water and trees and wind worked their own patterns of erosion on the Canyon walls, dislodging rocks that would tumble down towards the River below.
And here was another difference. As I hiked down in 1973 I kept an eye on the weather at the Canyon rim. I could l see clouds gathering and knew that it was snowing at the top. After reaching Skeleton Point and eating my sardines and crackers, I knew it was time to turn back in order to get out of the Canyon before the weather worsened. I was trudging up the last half mile in snow, leaving my footprints behind me. The wind was blowing the snow, and I had my hood up. Then I heard something. It sounded like the thumping of distant thunder. I put my hood back so I could hear better. There was a rumble and rattle of above me. I looked up and saw a good size rock rolling down the Canyon side in my direction. I took several steps backwards and watched as the rock landed on the trail where I had been standing and bounded further down and out of sight in the direction of the River.
I had witnessed the process of the Canyon. Things change. That rock is now in a different place and the level of the Canyon floor is now lower. And I can tell the difference.