Wolf advocates are celebrating the confirmation of the first documented litter of Mexican gray wolves born in the wild in Mexico since they disappeared nearly three decades ago.

Without giving their exact location, Mexico's National Commission for Natural Protected Areas confirmed the wolves were sighted in the western Sierra Madre mountains by a team of researchers and that the pups were doing well, according to the AP.

Mexican wolves, also known as lobos, once roamed vast portions of the Southwest and Mexico but were eradicated by the 1900s in the U.S. over conflicts with humans and livestock, while populations in Mexico dropped off. In 1976, they were listed as an endangered species and bi-national recovery efforts began the next year.

Mexico began releasing wolves in 2011, and released the parents last December in the hope they would breed.

"This first litter represents an important step in the recovery program, because these will be individuals that have never had contact with human beings, as wolves bred in captivity inevitably do," the commission said in a statement.

In the US, the Fish and Wildlife Service (FWS) approved the Mexican Wolf Recovery Plan in 1982, which recommended a captive breeding program and supported a goal of maintaining at least 100 wolves in their historic range, but progress has been slow and the agency's lack of action has been criticized by those who want to see a successful recovery for this species.

The first 11 wolves were released in the Blue Range Wolf Recovery Area in Arizona in 1998, but as of this January there were still only 83 in the wild in Arizona and New Mexico.

Unfortunately, the few who are out there continue to face threats that range from a lack of genetic diversity, diseases, conflicts with livestock, being killed by humans and hostility from those who don't want to see them return to their rightful place in the wild.

The FWS has recently proposed changes to its management plan that include both steps that would benefit them, but also changes that will make things worse.

Advocates of the lobo are urging the agency to immediately release more wolves into the wild, allow them to expand their territory, stop capturing and returning those who wander outside current boundaries, and to finish its long overdue recovery plan before it makes any official changes.

They're also asking the agency to remove the "nonessential" designation from the population in the wild. The FWS claims that even if all the ones in the wild disappeared, it wouldn't hinder recovery efforts because there are still many in the breeding program, but critics of that statement argue that the survival of those who have experience in the wild is critical to their future survival.

This August, the agency will release its draft Environmental Impact Statement and hold a public comment period, in addition to holding public hearings in Arizona and New Mexico.

To find out more about the proposal and how you can help support Mexican gray wolf recovery, visit mexicanwolves.org.