When a man admitted he pretended to be Bigfoot, many thought the question was answered. Others disagree.

Since the late 1800s, more than 3,000 sightings of Bigfoot, also called Sasquatch, have been recorded in the United States and Canada. The reports describe a tall, hairy, apelike creature that walks on two feet and has long arms and a short neck. The tracks, investigators say, show no claw marks like a bear would leave. Their size?averaging around 16 inches long and 7 inches wide?is bigger than any human print, and the long stride would be almost impossible for a person to make.

Jeff Meldrum, an anatomy professor at Idaho State University, has collected more than 200 plaster casts of tracks. He admits some of the tracks are fakes. But the majority, he says, are quite consistent, with flat, flexible feet; five toes; and qualities common to all primates. “Who could have made these traits so consistently if it’s all a hoax?” he says.

Researchers do expect some variations in the tracks. “If you were in a locker room and saw all the bare feet, there’d be a lot of variation,” says wildlife biologist John Bindernagel. “Something is walking around out there.” Researchers have also collected handprints, knuckle prints, knee prints?even butt prints!

The fact that no skeleton has ever been found doesn’t deter investigators, either. “We’re finding new fossil species all the time,” Meldrum says. “It only takes one to convince people Bigfoot exists.”

Many Bigfoot researchers say the 1967 home movie of a tall, hairy creature (image above) proves that Bigfoot exists. But in 2002, a man who seemed to know behind-the-scenes information about the movie claimed he had posed as Bigfoot in the film. Could Bigfoot be descended from an extinct giant ape called Gigantopithecus? Investigators say yes. But its fossils are found only in Asia, and there’s no evidence it migrated anywhere else. “We have no fossils of this primate in North America,” says anthropologist David Daegling of the University of Florida.

In fact, prints are the only physical evidence of Bigfoot, but many scientists say they’re too inconsistent to be trusted. “There are three-, four-, and five-toed varieties,” Daegling says. And given the number of reported sightings, critics say that the creatures should be having closer encounters with humans, such as one getting hit by a car. “The biggest argument against Bigfoot is that we don’t have a single body,” Daegling says.

“What we have to ask about the Bigfoot evidence is, ‘Is it possible that a human being could have produced this?’” Daegling says. “There is always another explanation besides a hairy monster.”