Tom Vail is an official guide in the Grand Canyon National Park, and for years he told his visitors how the extraordinary layer-cake rock formations had been dug out of the Colorado River valley over a period of millions of years.
That, though, was before Jesus entered his life.
Now he is convinced, along with a sizeable portion of America's creationist movement, that the formation of the Grand Canyon had nothing to do with evolutionary geology but was rather the product of a Biblical flood - the same one that Noah survived half a world away on Mount Ararat.
"Now, I have a different view of the Canyon, which according to a biblical time scale, can't possibly be more than a few thousand years old," Mr Vail writes in the introduction to a lavish picture book he has edited, entitled simply Grand Canyon: A Different View.
The book is causing consternation among mainstream scientists because, for the past few months, it has been on sale in the Grand Canyon National Park bookshop. Alongside the photographs, it includes essays by more than 20 prominent creationists who use much of the language, but little of the method, of science to support their literal reading of the Bible.
Most gallingly for secularists and scientific rationalists across the United States, the fundamentalist interpretation of one of the great natural wonders of the world appears to have the blessing of the Bush administration.
Not only has the National Park Service in Washington given every encouragement to the sale of Mr Vail's book, it has - according to one secular interest group called Public Employees for Environmental Responsibility (Peer) - blocked the publication of a detailed rebuttal of the arguments set out by Mr Vail's contributors.
PEER sees this as part of a pattern of what it calls "faith-based parks" policy. In a separate controversy, the Bush administration recently overruled the superintendent of the Grand Canyon park who wanted to remove three plaques inscribed with Biblical quotations overtly suggesting that the Canyon was the direct creation of God.
"The Park Service leadership now caters exclusively to conservative Christian fundamentalist groups," said Peer's executive director, Jeff Ruch.
The spat is a classically American confrontation between scientific evidence and religious belief - a cultural faultline that has grown more pronounced under the presidency of George Bush because of his own fundamentalist beliefs and reliance on the religious right for much of his bedrock support.
The controversy over Mr Vail's book began last summer, when a professor of geology from the University of California, visited the Grand Canyon bookshop and raised a ruckus over its inclusion in the natural sciences section. In a subsequent review for the journal Eos, the professor, Wilfred Elders, characterised the book's arguments as "absurdities".
But the book has proved so popular that it has sold out and the bookshop has had to reorder it from its publisher.
Mr Vail's friends are delighted, both by his success and by the controversy itself. His publishing house, Arksansas-based New Leaf Press, has described the dispute as "the next battlefield in the struggle for Christian rights". On that point, at least, the creationists may well be correct.Reuse content