AUGUSTA, Maine —  Sorry, cougar believers. The “ghost cat” of the eastern woods is no more.

Or at least that’s the official word from the U.S. Fish and Wildlife Service, which has determined after a three-year study that the species of cougar that once prowled from Michigan to Maine to South Carolina is extinct.

As a result, the agency plans to move forward with plans to remove the eastern cougar from the federal endangered species list, officials announced Wednesday.

That conclusion is unlikely to convince the hundreds — perhaps thousands — of Americans who believe they have spotted one of the elusive “big cats” crossing a road, stalking prey in a field or even sunning itself in a backyard in the eastern United States. Maine wildlife officials receive dozens of reports every year.

But after reviewing more than 570 comments from the public on possible sightings, federal biologists determined that any cougars spotted north of Florida were likely captive cats that were released or escaped, western cats migrating eastward or — in most cases — were not mountain lions at all.

“We recognize that many people have seen cougars in the wild within the historical range of the eastern cougar,” Martin Miller, the service’s northeast region chief on endangered species, said in a statement on Wednesday. “However, we believe those cougars are not the eastern cougar subspecies. We found no information to support the existence of the eastern cougar.”

Also known as pumas, panthers or catamounts, cougars are the most widely distributed land mammal in the world besides humans. Adult cats typically range from 75 to 150 pounds — much larger than Maine’s other wildcats, the bobcat or Canada lynx — and are distinguishable by their tawny color and long, thick tail.

The eastern subspecies was once abundant but was driven to extinction by humans in much of its former range by the late-1800s or early-1900s. The last confirmed eastern mountain lion was killed by a trapper in Somerset County, Maine, in 1938.

The cat was added to the federal endangered species list in 1973,  based on beliefs that small populations of the lions may survive in the southern Smoky Mountains. But despite frequent sightings and a small number of documented cougars — including at least two in Maine — biologists say wild breeding populations of mountain lions have not been found since.

Mark McCollough, a USFWS biologist in the agency’s Old Town office who led the review, said it is not a pleasant experience for biologists to acknowledge that eastern cougars are likely extinct. And as someone who investigates cougar sightings in Maine along with the state Department of Inland Fisheries and Wildlife, McCollough said he understands the intense interest in the species.

But McCollough stressed that the review’s extinction finding does not mean that the Fish and Wildlife Service denies that cougars turn up from time to time. They do, he said, and the department fully acknowledges that fact. The agency simply doesn’t believe they are wild, eastern cougars, he said.

“Indeed, cougars do show up and one could be coming to Maine tomorrow,” said McCollough, who is the author of the 107-page report. “But I believe it would probably be an escaped pet.”

Maine wildlife officials still receive scores of reports from areas all over the state. But without a carcass, live animal or other concrete evidence, biologists say there is no scientific proof that a wild population of cougars exists anywhere in the state.

McCollough’s report contains a listing of more than 100 published records of eastern cougars in Canada and the U.S. going back to 1900. In addition to the cat killed in 1938, there are two more recent cases in Maine in which biologists found evidence to support the eyewitness report.

The first, in 1995, took place in Cape Elizabeth. Hair samples collected from the site identified the cat as a cougar. The second, well-documented case happened in 2000 when an experienced outdoorsman who was scouting out possible hunting spots watched for several minutes as a female with a kitten in tow walked near railroad tracks in Monmouth. Biologists determined the tracks came from a mountain lion.

The USFWS will now begin the formal process of removing the eastern cougar from the endangered species list, which will involve gathering public comment.

While delisting the cougar will eliminate federal protections for the cat, it does not force states to remove their own legal protections for mountain lions, McCollough said. DIF&W representatives could not be reached for comment Wednesday on the federal decision. It would still remain illegal to hunt or trap a cougar in Maine because there is no open season for the species.