The mountain lion killed by a car in Milford in June probably traveled 1,500 miles from its birthplace in the Black Hills of South Dakota before dying on the Wilbur Cross Parkway in Connecticut, the state Department of Energy and Environmental Protection.

This mountain lion's trip was the longest one documented for a mountain lion and quite possibly the longest undertaken by a mammal in North America, said DEEP wildlife biologist Paul Rego.

"It was an incredible journey that ended in a tragic death on our highway here," said Daniel C. Esty, commissioner of the DEEP.

Young male cougars often roam up to 100 miles in search of breeding opportunities, open habitat and food resources, said Rego, but this cat's journey was an anomaly, more than double the longest previously documented journey of about 640 miles.

Genetic testing revealed that the big cat came from a wild breeding population of about 250 mountain lions in the southwest corner of South Dakota, the Black Hills area, results released Tuesday afternoon revealed. No one knows why the animal — a lean, 140-pound male between 2 and 4 years old — undertook a journey across the continent. But its travels were documented through Minnesota and Wisconsin, and biologists speculate that the cat then wandered through southern Ontario and New York before reaching Connecticut.

Nicknamed the St. Croix mountain lion during his time in Wisconsin, the cat was definitively linked to four sites in the two states through genetic testing of scat, blood and hair found in the snow during late 2009 and early 2010. He also was captured on video by trail cameras. Additional mountain lion sightings were confirmed at eight other sites in Minnesota and Wisconsin, but could not be linked to the same animal.

The DEEP said that a necropsy in Connecticut turned up no evidence that the mountain lion had ever been a captive creature — he had no microchip, nor was he neutered or declawed. His stomach was empty at the time of his death, although porcupine quills were found in his subcutaneous tissue, an indication that he had spent time in the wild, said Rego.

The results came as a surprise to DEEP officials and to biologists across the country, said Rego, who originally believed the mountain lion was a captive animal that had escaped or was released.

"It is a testament to the adaptability of this species that it could travel from South Dakota to Connecticut," Esty said. "It is a symbol, perhaps a signal of a stronger bounce back of some of our wildlife species."

Although biologists do not know how the mountain lion made its way from Wisconsin to Connecticut, Rego said it is more likely that the big cat moved through southern Ontario, rather than going into the populated area south of Lake Michigan.

Scientist may never determine why the big cat roamed so far, but DEEP Deputy Commissioner Susan Frechette said ongoing tests may reveal details of his travels, including the food he ate as he moved east. The animal was not rabid and did not have any physical abnormalities that might explain the extreme roaming, said the DEEP.

The June 5 sighting of the mountain lion in Greenwich, confirmed through DNA testing to be same animal hit and killed by a car on the Wilbur Cross Parkway on June 11, was the first confirmed sighting in the state since the 1880s.

Despite a number of reported sightings over the years (the state receives 10 to 12 unconfirmed reports each year), the DEEP says that there are no native mountain lions in Connecticut. The Eastern mountain lion was declared extinct in March by the U.S. Fish and Wildlife Service.

Mountain lions are regularly reported throughout the Northeast and other areas where the animals are not known to live, but besides the mountain lion killed in Milford, the only concrete evidence of an animal in the recent past was a skull found inMassachusetts.

Adrian Wydeven, a mammal ecologist with the Wisconsin Department of Natural Resources, said that mountain lions' populations are higher now that at any other time over the past 100 years, and that Midwestern states such as Wisconsin, Minnesota and Iowa without native populations are now seeing some mountain lions.

As to the far-roaming animal's future, Rego said several museums have expressed interest in displaying the animal after a taxidermist has preserved the body. The body is now in a freezer pending further tests, and no decisions have been made, he said.