The guide, a soft-spoken fellow with a scholarly aspect, walks through the halls of this handsome, half-finished museum and points to the sculpture of a young velociraptor.

"We're placing this one in the hall that explains the post-Flood world," explains the guide. "When dinosaurs lived with man."

A reporter has a question or two about this dinosaur-man business, but Mark Looy -- the guide and a vice president at the museum -- already has walked over to the lifelike head of a T. rex, with its three-inch teeth and carnivore's grin.

"We call him our 'missionary lizard,' " Looy says. "When people realize the T. rex lived in Eden, it will lead us to a discussion of the gospel. The T. rex once was a vegetarian, too."

The nation's largest museum devoted to the alternative reality that is biblical creation science is rising just outside Cincinnati. Set amid a park and three-acre artificial lake, the 50,000-square-foot museum features animatronic dinosaurs, state-of-the-art models and graphics, and a half-dozen staff scientists. It holds that the world and the universe are but 6,000 years old and that baby dinosaurs rode in Noah's ark.

The $25 million Creation Museum stands much of modern science on its head and might cause a paleontologist or three to rend their garments. But officials expect to attract hundreds of thousands of visitors when the museum opens in early 2007.

"Evolutionary Darwinists need to understand we are taking the dinosaurs back," says Kenneth Ham, president of Answers in Genesis-USA, which is building the museum. "This is a battle cry to recognize the science in the revealed truth of God."

"Intelligent design," the theory that the machinery of life is so complex as to require the hand -- subtle or not -- of an intelligent creator, has stolen the media thunder of late. This week a trial will begin in federal court in Pennsylvania, in which 11 parents accuse the Dover school board of violating the separation of church and state by requiring high school biology teachers to read a statement in class that intelligent design is an alternative explanation of life's origins.

Most scientists dismiss intelligent design as flawed science, and they fear cultural conservatives intend it as a religious wedge. The small band of scientists who promote intelligent design retort that theirs is a scientific inquiry, albeit with theistic implications.

But by any measure, Young Earth Creationism -- which holds that the Bible is the literal word of God and that He created the universe in seven days -- has a more powerful hold on the beliefs of Americans than evolutionary theory or intelligent design. That grip grows stronger by the year.

Polls taken last year showed that 45 percent of Americans believe that God created humans in their present form 10,000 years ago (or less) and that man shares no common ancestor with the ape. Only 26 percent believe in the central tenet of evolution, that all life descended from a single ancestor.

Another poll showed that 65 percent of Americans want creationism taught alongside evolution.

In the early 20th century, many creationist thinkers viewed Genesis as metaphorical, accepting that Earth formed over hundreds of thousands, even millions of years. But as society became more secular, and science offered an implicit challenge to fundamentalist beliefs, creationist leaders took a more literal line.

"The creationists have been very successful in persuading conservative Christians to abandon any nonliteral interpretation of the Bible," said Ronald L. Numbers, a professor at the University of Wisconsin at Madison and author of "The Creationists." "There is a very large constituency of Americans who are quite comfortable with Young Earth Creationism."

To drive past the stegosaurus silhouettes at the gate to the parking lot at the Creation Museum here is to enter a creationist world in great ferment. Answers in Genesis is one of about a half-dozen creationist organizations and museums, each with its own headquarters, radio studios and Web sites, and scholarly and popular magazines. (A family-oriented column even ferrets out covert evolutionary messages in "Finding Nemo" and "My Big Fat Greek Wedding.")

Another creationist museum launches expeditions to the Papua New Guinea highlands in search of living pterodactyls.

All of this -- creationist zoology, paleontology, archaeology -- is framed in a distinctive academic language.

So one reads of post-Babel studies, and floodology and post-diluvium studies, these being the study of the world after Noah and the Great Flood, which is regarded as purest fact. The sanctified imagination, which is to say inspired by God, helps the scientists and artists at Creation Museum re-create the world of Adam and Eve, from sauropods playing with children to the "humongous" mature trees that God created in a single day.

"Our artists anticipated some challenging . . . work," the Answers of Genesis Web site notes.

Young Earth Creationists emphasize the rigor of their science. Looy rattles off the names of experts with doctorates, many of whom obtained degrees from mainstream universities. A creationist scientist, Kurt Wise, worked as a graduate student at Harvard with prominent biologist Stephen Jay Gould. John Baumgardner of the Los Alamos National Laboratory became a well-regarded designer of computer models for planetary catastrophes.

They herald successes. Recent discoveries by geologists tend to support creationists' beliefs that great floods -- albeit not necessarily ordered up by God -- played a role in gouging out some canyon lands.

But often, scientists say, the creationist bottom line is a through-the-looking-glass version of science. The scientific method of theory, experiment and assumptions upended does not apply. Ask Ham if he could accept evidence that conflicts with his reading of Genesis -- proof, say, that a fossil is more than 6,000 years old -- and he shakes his head.

Creationists believe man became mortal when God cast Adam and Eve out of Eden 6,000 years ago. Death did not exist before that.

"We admit we have an axiom: We have a book and it's the Bible and it's revealed history," says Ham. "Where the Bible teaches on science, we can trust it as the word of God."

Scientists place the age of Earth at 4.5 billion years. Many tend to act resigned at the mention of creationists, seeing a worldview so different as to defy debate.

"There are people who are prepared to accept that the universe is a pretty untidy place," said Ian Tattersall, a curator at the American Museum of Natural History. "And there are people, like the creationists, whose minds rebel at this notion."

Ham, whose voice carries broad hints of his native Australia, is a charismatic speaker and skilled debater, and he has built Answers in Genesis into the world's leading creationist organization in less than a decade. He raised nearly $20 million to build the museum, and the average donation was about $70, officials say.

Answers in Genesis hews to no particular evangelical line. Ham's politics lean strongly to the right, seeing America as under siege by homosexuality and abortion. In a recent column for the Rev. Jerry Falwell's newspaper, Ham described his mission as "fighting the 'Philistines' of our day."

"By and large, much of the church has compromised God's Word in Genesis by allowing millions of years and evolutionary ideas to be embraced by God's people," Ham wrote. "We need to take back the maligned Grand Canyon, the majestic mountain ranges, the massive coal beds . . . and the dinosaur fossils."

Ham is ambivalent on the question of intelligent design. He admires the movement's founders and applauds their battles. But he is skeptical of creationists who see intelligent design as a battering ram that might smash down the constitutional doors and allow the Bible back into schools.

"They are not a Christian movement, they are not about the Bible," he says in his spacious corner office at the museum. "It's not even against evolution, not really, because they don't tell you what that intelligence is. It could open a door for Muslim belief, for Hindus, for New Age.

"We are telling you unashamedly that the word of the Bible is the way."

"This is a battle cry to recognize the science in the revealed truth of God," said Kenneth Ham, who raised funds for the Creation Museum.