Kathleen Kavarra-Corr
My name is Dr. Kathleen Kavarra-Corr.
Bernadette Kane-Cole
And my name is Bernadette Kane-Cole. What happened to Zion Canyon in the 1930s?
Kathleen Kavarra-Corr
For me, this has been a detective story. I came here in 2000 to be a ranger, and I fell in love with the place. And so I'm out there talking to folks and picking up trash, and I see this 18 inch piece of a quarter inch rusted iron, and I go over to it, and I bend down to move it, and it just doesn't move! What the heck is under this trail?
Realizing, you know, I need to read up the history of this canyon. When you go into the archives, every one of these books has a chapter on floods, there were a number of comments saying, "We're worried about the river"; "We need to protect the lodge"; "The river is the devil's work"; "The river is an angry woman raging"; "The river will never be tamed," and I'm going to myself, "I'm in the desert. What the heck are these histories, talking about floods?"
And that first year, when I was working, I ran into a ranger, and she said to me, "Oh, by the way, you should know there are hardly any young cottonwood trees in the canyon."
Huh? What is she talking about?
I was enamored with the cottonwood trees as they were — so beautiful, and the wind in the leaves was just entrancing and enchanting.
I see that there's something under the trails. I'm reading about floods, and I'm hearing there's something wrong with the cottonwood trees. I feel like I was a detective on a cold case.
So what happened in the 1930s was that they had a single gasoline powered, one-bucket shovel. They brought in these giant wire cages called revetments, and filled them with rock that they blasted off the mesa.
And with that, the government put false river banks in Zion Canyon, and in so doing, they separated the flood plain from the river. Originally, the water touched the river banks, the cottonwood trees would sprout in the wet, sandy soil. That's how cottonwood trees sprout.
Bernadette Kane-Cole
Eventually, you're like, "Oh, there's something missing."
Kathleen Kavarra-Corr
Why would you do all this in an area where it only gets 15 inches of rain a year — at most? I had a light bulb, and I said, "there must have been a climate change here that has been forgotten." So that led me to all this research. I found a tree ring study that said that from 1905 to 1922 was the wettest period in the American Southwest in 1,425 years. These pieces all fit together,
Bernadette Kane-Cole
And what has been the result?
Kathleen Kavarra-Corr
Our beautiful cottonwood forest is dying, and there's nothing to replace it.
Bernadette Kane-Cole
So it sounds like in relation to this increase in precipitation that was unheard of and then went away — what we're dealing with is unintended consequences. And is it dire?
Kathleen Kavarra-Corr
Oh, yeah. So to fix this, if we remove the false river banks, take that rock and armor the road instead, the canyon will heal itself.
Bernadette Kane-Cole
And is there anything that we can do to help?
Kathleen Kavarra-Corr
Yeah! Contact Senator John Curtis or any Federal House representative in the state of Utah and ask them to put the money for the restoration of Zion Canyon into the federal budget so we can get this done.
Kathleen Kavarra-Corr's full dissertation can be found here:
Perceptions of Historical Climate Change and Park Policy: The Impact on the Fremont Cottonwood in Zion National Park
