“How did the Grand Canyon form?” is a question so commonly pondered that YouTube is rife with explanations. Go down into the long tail of Grand Canyon videos, and you’ll eventually find a two-part, 35-minute lecture by Andrew Snelling. The first sign this isn’t a typical geology lecture comes about a minute in, when Snelling proclaims, “The Grand Canyon does provide a testament to the biblical account of Earth’s history.”

Snelling is a prominent young-Earth creationist. For years, he has given lectures, guided biblical-themed Grand Canyon rafting tours, and worked for the nonprofit Answers in Genesis. (The CEO of Answers in Genesis, Ken Ham, is also behind the Creation Museum and the Ark Encounter theme park.) Young-Earth creationism, in contrast to other forms of creationism, specifically holds that the Earth is only thousands of years old. Snelling believes that the Grand Canyon formed after Noah’s flood—and he now claims the U.S. government is blocking his research in the canyon because of his religious views.

Last week, Snelling sued park administrators and the Department of Interior, which administers the national parks program, because they would not grant him a permit to collect 50 to 60 fist-sized rocks. All research in the national park is restricted, especially if it requires removing material. But the Grand Canyon does host 80 research projects a year, ranging from archaeology digs to trout tracking.

Alliance Defending Freedom, a Christian legal advocacy group that filed the lawsuit on behalf of Snelling, alleged discrimination by the park. “National Park Service: Research in Grand Canyon okay for geologists … but not Christian ones,” read the headline on their press release. (Interior department and NPS spokespeople declined to comment because of the pending litigation.)

If the permit application hit a nerve, it’s because young-Earth creationists have a bit of an obsession with the Grand Canyon. Where geologists see billions of years of rock layers carved out by a persistent flow of water, young-Earth creationists see sediments laid down in Noah’s flood. As the flood receded, they believe, water became trapped behind natural dams, until it finally broke through in a “catastrophic erosion” that carved the Grand Canyon.

This is the story told on religious rafting trips organized by companies like Canyon Ministries, for which Snelling also works as a guide. In 2004, a book by the Canyon Ministries founder Tom Vail caused a stir when it was sold at the national park’s bookstores.

It’s all part of an uneasy relationship between the park and young-Earth creationists. The park does permit the rafting trips, and it has allowed creationists, including Snelling according to the lawsuit, to work in the park before. Another prominent young-Earth creationist, Steve Austin, took photos of nautiloid fossils in the park and used them to argue that the creatures died during the flood. “I think the NPS has felt a bit stung by past creationist research in the Grand Canyon,” says Steven Newton, who teaches geology at College of Marin and serves as the programs and policy director for the National Center for Science Education, a nonprofit that opposes teaching creationism in public schools.

Exactly why the park did not grant Snelling’s application is, of course, now the subject of a lawsuit. His project did involve collecting a sizable number of rocks, which can invite more scrutiny. In an email to Snelling filed as part of the lawsuit, a park officer said the project was not granted because the type of rock he wanted to study can also be found outside of the Grand Canyon. The park solicited peer reviews from three mainstream geologists. One mentioned the rocks could be found elsewhere; all three overwhelmingly denounced the work as not scientifically valid, a criterion the park also uses to evaluate proposals. Snelling, who holds a Ph.D. in geology, did not disclose his Answers in Genesis affiliation, nor did he explicitly say he wanted to prove the Grand Canyon is young in his initial permit application, but the reviewers became aware of his reputation.

(Roger Bolsius / Creative Commons)

Geology as a profession has struggled with what to do with young-Earth creationists, whose beliefs are contradicted by literal mountains of scientific evidence. Shut them down, and you get cries of censorship—like this lawsuit. “This just so plays into their hands,” Newton says about the national park’s treatment of Snelling’s application. Newton favors letting creationists do their research and then arguing on the merits of their science. But allowing them to present at scientific conferences, others say, is lending creationists legitimacy.

“That’s really a tough question because in science we want to be the type of community where people can bring about ideas that are controversial,” says Stephen Moshier, a geologist at Wheaton, a Christian liberal arts college in Illinois, and a former president of the Affiliation of Christian Geologists. The problem, according to Moshier, who is not a young-Earth creationist, is that they want mainstream geologists to be open to new ideas, but it’s the young-Earth creationists themselves who have proved inflexible in the face of new evidence contradicting their ideas. “Often I read things by young-Earth creationists where I think they really ought to know better. Many of them have excellent training in the geosciences,” he says. (Snelling declined to comment because of the lawsuit. Four other young-Earth creationists who study the Grand Canyon did not respond to requests for comment.)

That the Grand Canyon is the stage where this conflict now plays out is no coincidence. The canyon is such a potent example of the power of small changes over time—of what’s possible on geological time scales. “Look through any introductory geology textbook, any sedimentology textbook, and the Grand Canyon is going to be there in either full color or on the whole page,” says Moshier.  

Last year, he and other Christian geologists published a book titled The Grand Canyon, Monument to an Ancient Earth, directly refuting young-Earth creationists who cite the canyon as evidence of Noah’s flood. “It wouldn’t be of any use writing about the Appalachian Mountains—even though I think we can make a stronger case for an ancient Earth there because the geology is so complex,” says Moshier. “Because they make a big deal out of the Grand Canyon and use it as a lab for young-Earth creationism and flood geology, that’s naturally where we had to focus the book.”

When young-Earth creationists invoke God, they are tapping into a real sense of wonder about the Grand Canyon. It’s easy—in fact all too human—to wonder how so small a river could have carved so vast a chasm. One partial answer is that the Glen Canyon dam has quelled the spring floods that originally bored through rock; the lazily winding Colorado River that you see today is not the river that formed the Grand Canyon. But also, humans are bad at intuiting the consequences of deep time. Once you add enough zeros to number of years they all start to sound the same.

It’s hard to imagine how much can happen in geological time. About 1.7 billion years ago, a series of volcanoes crashed into what would become the continent of North America and created mountains taller than the Himalayas today. Those mountains eroded back down to hills to form the rock that now rests at the base of the canyon. Over countless millions of years, a shallow sea expanded and contracted over the area, laying down the sediment that would become the sandstone, shale, and limestone layers. Plate tectonics then pushed those rock layers up and up to became the Colorado Plateau. And finally, flowing water carved its way down 1.7 billion years of rock.

It’s hard to imagine, but there is wonder and grandeur in this imagination, too.