The Phoenix Zoo lost its beloved mountain lion, Sierra, who was humanely euthanized this week after dealing with advanced ...

The Phoenix Zoo will break ground this week on a new veterinary medical center. The 27,000-square-foot building will provide ...

Zoo staff made the difficult choice to euthanize one of the zoo’s two female mountain lions, Sierra, earlier in the week.

The Phoenix Zoo and Reid Park Zoo in Tucson are both dealing with the loss of longtime residents. The Phoenix Zoo lost its beloved mountain lion, Sierra, who was humanely euthanized this week ...

The Phoenix Zoo lost one of its longtime residents this week. Sierra, a mountain lion, was humanely euthanized due to ...

The zoo said zookeepers and veterinary staff made the "difficult decision" to put down mountain lion Sierra earlier this week ...