(CNN) -- Two dozen lions rescued from harrowing conditions at circuses in Bolivia have a new home in Colorado, where they will live outside of cages and roar at the distant Rocky Mountains.
Animal Defenders International (ADI) brought them last week to Denver, where they were transported to the Wild Animal Sanctuary, to conclude its "Operation Lion Ark."
The flight followed the passage of a 2009 law in Bolivia that bans the use of any animals in circuses.
The 25 felines are currently housed in a 15,000-square-foot temporary biosphere, complete with grass, trees and other natural features, at the sanctuary in Keenesburg, about 30 miles northeast of Denver.
They're sleeping better, are getting exercise and have begun to roar in unison, "which demonstrates they are beginning to bond as we expected," said Pat Craig, executive director of the sanctuary.
The ADI campaign and airlift got a big financial boost from TV game show host Bob Barker.
Barker and actress Jorja Fox of "CSI" described the campaign Wednesday night on HLN's "Jane Velez-Mitchell.
"It is a true testament to the Bolivian people what they were able to accomplish quickly," Fox said of the law and the rescue of the lions, which were part of eight circuses.
Of the 25 lions, 24 were seized from circuses, many the traveling variety. Eight were living in a cage pulled by a truck, Fox said, and at least two had never seen other lions.
The sanctuary is building a permanent 80-acre fenced site for the lions, which will live in four prides, Craig told CNN.
They'll get along just fine with the climate in Colorado, he said, because they are exposed to the cold in North Africa.
Living in Bolivia put them in a much warmer climate that will require acclimation until they are released into the permanent living area in late March or April.
"It was a surprise to me to know that lions are genetically wired for winter," said Fox.
The 320-acre sanctuary of rolling grasslands, split into habitats, houses more than 275 large carnivores, including bears, tigers and other big cats.
The Wild Animal Sanctuary emphasizes its mission is to serve as a sanctuary, not for entertainment.
"It's a home for animals, not a zoo for people," Craig said.
Animal rights activists and groups are optimistic that Bolivia's 2009 action will lead other countries to ban animals in circuses and change conditions in zoos.
"I'm against zoos. I consider them prisons for animals," Barker told HLN.
The sanctuary uses proceeds from its annual 50,000 visitors to cover the costs of their visit, Craig said. "We hope they become long-term contributors."
About 80 percent of the carnivores at the facility, which costs about $2.5 million a year to operate, were in the United States when they were seized from deplorable or illegal situations, he added.
Most of the lions will have a lifespan of about 21 to 23 years, double their expected longevity in the wild. That's largely because they have no predators or competition from within their population.
Lionesses receive estrogen implants so that they won't go into heat. That reduces the competition and fighting among males.
Craig praised Bolivia for taking action.
"This is the first country that stepped up," he said.
He expects Peru, Ecuador and other countries to take steps that eliminate or limit the use of animals in circuses and other entertainment venues. Cities and states in the United States are taking a hard look at the treatment of elephants and carnivores, according to Craig.
The 25 lions are adjusting well, appear calm and enjoy stretching their legs while running and playing.
"Like many rescued animals that come from extreme captive situations, they are quickly accepting all of the positive changes that are happening," Craig told CNN. "There is nowhere to go but up when you have lived at the bottom, so they are open to grasping every opportunity to enjoy life that we present. This will continue all the way until they are roaming freely in large acreage habitats, when they can complete their journey."
CNN's Phil Gast contributed to this report