Amateur fossil hunters were expected to attend Saturday's dedication of the abandoned Union Chapel Mine as a preservation site that contains evidence of prehistoric life.

The Walker County coal mine, now owned by the state of Alabama, is believed to be one of the world's best places to find Coal Age trace fossils.

As an example of that, Prescott Atkinson tapped at a seam in a chunk of shale discarded from the mine. It came cleanly apart, revealing the tracks of an oversized prehistoric amphibian.

''Sometimes, it will open up like a book opens. It's a page of history,'' Atkinson said as he pointed to distinct footprints on the surface of the shale. ''An animal about the size of a cat or small dog walked across here.''

New Mexico paleontologist Spencer Lucas called the mine the Rossetta Stone for understanding Coal Age life and some of the earliest animals to walk on four legs.

The public is invited Saturday to hunt for traces of ancient amphibians, oversized insects and prehistoric fauna pressed in the layers of flaky rocks. The site dedication marks a five-year effort by a determined band of amateur paleontologists to keep the Union Chapel Mine from being reclaimed and its fossil treasures lost.

Atkinson, a UAB pediatric researcher, said the site is being dedicated as the Steve C. Minkin Trackway Fossil Site. Minkin was an Anniston geologist who campaigned for the site's preservation and who died from a fall at his home in February.

On a 2000 field trip, Minkin and fellow members of the Alabama Paleontological Society recognized the value of the site. They also discovered that New Acton Coal Co., which owned and had mined the site, was required by federal law to demolish the exposed hillside and cover the whole thing with vegetation.

That set them on a scramble to document the site, raise awareness and persuade the government to help.

They gathered the support of scientists across the country and abroad, and persuaded U.S. Rep. Robert Aderholt, R-Ala., to introduce federal legislation to have the mine exempted from the Surface Mine Reclamation Act. They also won cooperation of the coal company, the Alabama Surface Mining Commission and the Alabama Department of Conservation and Natural Resources.

The group raised $30,000 to help the state buy the 32 acres.

Hartmut Haubold, director of the Institute of Geological Sciences at Martin Luther University in Germany, is one of the most respected experts on fossil trackways and visited the mine site. He wrote in support of its preservation: ''My assessment: By quantity, by quality, and by geologic age, it is the most important discovery of Carboniferous tracks hitherto known.''

Amateur paleontologists have carefully catalogued their finds. University of Alabama astronomer Ron Buta has indexed and posted 3,000 photographs of tracks on a Web site, making the finds available to people around the world.

On the Net:

http://bama.ua.edu