Montana ? Gray wolves in the Northern Rockies will be removed from the endangered species list, following a 13-year restoration effort that helped the animal’s population soar, federal officials said Thursday.

An estimated 1,500 wolves now roam Idaho, Montana and Wyoming. That represents a dramatic turnaround for a predator that was largely exterminated in the U.S. outside of Alaska in the early 20th century.

The restoration effort, however, has been unpopular with ranchers and many others in the three states since it began in the mid-1990s, and today some state leaders want the population thinned significantly.

The states are planning to allow hunters to target the animals as soon as this fall. That angers environmental groups, which plan to sue over the delisting and say it’s too soon to remove federal protection.

Plans submitted by Idaho, Montana and Wyoming indicate the states will likely maintain between 900 and 1,250 wolves for the foreseeable future, federal officials said.

Wolves have increasingly preyed on livestock as they expanded into new territories. At the same time, ranchers and wildlife agents have made more wolf kills, which are allowed under the Endangered Species Act in response to livestock conflicts.