BILLINGS, Mont. (AP) — Federal officials say it could take two years or more to finish a long-delayed recovery plan for Canada lynx after a judge ordered the government to move forward with the work.

The snow-loving wild cats were listed as a threatened species by the U.S. Fish and Wildlife Service in 2000. After the agency repeatedly missed its own deadlines to start work on a recovery plan, environmental groups sued last year in federal court in Montana.

U.S. District Judge Donald Molloy on Thursday gave the government 30 days to schedule the work. Fish and Wildlife Service Assistant Regional Director Mike Thabault said Friday the plan could take a long time to complete because of the complex threats faced by lynx. The animals' range includes 14 of the Lower 48 states.