Bolivian lions arrived by aircraft in Keensburg, Colorado.
The Animal Defenders International arranged for their rescue through Operation Lion Ark, an investigation on the cruelty of animals in South American countries.
Former host of The Price is Right, Bob Barker, and CSI's Jorja Fox are both active with the foundation, and were on hand to welcome the lions.
The lions experienced the feeling of grass for the very first time in their new homes.
After less than 48 hours, the lions once described as "skinny," and "malnourished" are adapting "very well" according to the Sanctuary.
The Sanctuary reports that some of the lions who had never before socialized with others were walking around and "speaking (loudly)" to neighbors.
The lions will be fed 10-pound blocks of meat and nutrients six to eight times per day to promote muscle growth.
Among the "firsts" for the lions is the opportunity to play around.
The lions have the opportunity to relax without having to preform tricks or tasks.
Also available to the lions are trees, large logs, and heavy duty zoo balls.
After an adjustment period the lions will be moved to an 80-acre area with underground dens that will be kept at 60 degrees year round.
Twenty five Bolivian lions arrived at The Wild Animal Sanctuary in Keensburg, Colorado last week after their home country banned the use of animals for entertainment.