A mountain lion killed on a road in the US state of Connecticut had walked halfway across the US before it died in June, scientists have said.
DNA tests showed the cat was native to the Black Hills of South Dakota, 1,800 miles (2,896km) away, scientists said.
And its DNA matched that of an animal collected by chance in 2009 and 2010 in the states of Minnesota and Wisconsin.
The evidence suggests the cat made one of the longest-ever recorded journeys by a land mammal, scientists say.
The mountain lion, also known as a cougar or a puma, is a type of big cat native to the Americas.
The species once ranged widely, from British Columbia in Canada to Argentina and Chile, and from the Pacific Ocean to the Atlantic, but its habitat in North America is now mostly limited to the western US and Canada, according to the US Fish and Wildlife Service, a government agency dedicated to the management of fish, wildlife and habitats.
When it was struck by a car and killed in June in Milford, Connecticut, about 50 miles north-east of New York City, the young, lean, 140lb (64kg) male became the first mountain lion seen in that state in more than a century, said Daniel Esty, commissioner of the state's Department of Energy and Environmental Protection.
"The journey of this mountain lion is a testament to the wonders of nature and the tenacity and adaptability of this species," Mr Esty said
The continental crossing from South Dakota to Connecticut put the cat on a path south around Lake Michigan, passed Chicago, the old industrial "rust belt" cities of Ohio and western Pennsylvania and north of New York City.
According to scientists with the US Department of Agriculture, DNA taken from the mountain lion showed its genetic structure matched a population of cats native to the sparsely populated Black Hills region of South Dakota.
The DNA also matched samples taken from hair and blood in Minnesota, directly east of South Dakota, and Wisconsin, which neighbours that state to the east, in late 2009 to early 2010.
On 5 June, the lion was seen at a school in Greenwich, Connecticut. It was struck and killed on 11 June about 01:00 local time.
In addition, scientists said the cat was neither declawed nor neutered, suggesting it was not an escaped or released captive.