A couple of weeks ago, in the beginning of February, we took a few days off and went on a road trip to Sedona, Arizona. We spent one day hiking in the red rocks. The Devil’s Bridge is a popular hike north of town. It’s 1.8 miles from the trailhead, so about 3.6 miles round trip. The Devil’s Bridge is a natural rock bridge and definitely worth the hike.
The trail is well marked. It inclines gently for most of the way, but starts getting steeper during the last half mile, simply because it climbs up a cliff.
Speaking of cliffs, I noticed this major red rock, which is so typical for the Sedona area. As the hike went on, we kept getting closer to this wall, and I noticed a “band” in the red rocks. So you can see what I am talking about, I took the same photograph as above and put a green arrow on it. You can click to enlarge any of the photographs.
The arrow points to a narrow and slightly lighter-colored band. I found the same band on many other landmark rocks in the area. As I got closer to the wall, I took another picture:
Here you can see it more pronounced. And this got me thinking about the geology of Sedona and, for that matter, the entire Colorado Plateau, which includes the Grand Canyon. The large layers of red rock we find in Sedona are also visible in the Grand Canyon, about 600 feet below the rim. I have hiked through that red rock area many a times on hikes in the Grand Canyon, of course.
The red wall is called the “redwall limestone” area. It is in the Mississippian layer of the Colorado Plateau, which is about 340 million years old. The red layers are about 500 to 800 feet thick. Since the band I am pointing about is toward the lower end of the red rocks, I might estimate that his was laid down about 300 million years ago.
And that is the mindboggling feeling: 300 million years ago, when what is now the Colorado Plateau, was at the bottom of an ocean, there was a period where the sediments, for whatever reason that I am sure professional geologists can explain, were lighter than the red layers above and below them. Not only that, the rock is more brittle and the chunks seem to be larger. So for maybe 5 million years, the sediments in that sea collected this different band, until the red limestone layers came back on top of it.
5 million years!
And here I get to stand and take a picture of that band of rock that is now lifted up to 5,000 feet above sea level to show to you here.
Most people don’t realize that the Colorado Plateau is still being lifted up by about one inch in a human lifetime. In geological scales, that rising rapidly. The Grand Canyon is still being formed in front of our eyes, and the red rocks of Sedona are still growing in their glory.
And that is what I was thinking about all the way up to Devil’s Bridge.
When we finally got there, in the afternoon, the light was just “wrong” for a good photograph:
You see above, if you look carefully, the single hiker in the middle of the picture is standing on top of a natural bridge. You definitely want to click on this one to enlarge it. The valley far below behind him is so lit up that it’s difficult to catch the grandness of the bridge itself. If you look carefully you can see the void below.
On the way back down, I took another picture looking back up:
It’s hard to make out what you’re looking at, so I’ll put some more arrows on it:
The green arrow points to the natural bridge from below. Here you can see the depth of the void below the bridge from the other side. The blue arrow points to some people who are standing approximately where I was when I took the picture from above. And yes, you had to climb up that wall through a series of steps cut into the rocks which got a little scary at times.
Overall, hiking in Sedona is a wonderful experience and one day was nowhere near enough. We need to go back and hang out much, much longer.