State legislators have given initial approval to a bill that would allow ranchers to kill Mexican gray wolves caught attacking humans or livestock.

The Mexican gray wolf, which once roamed large portions of the Southwest, has been listed as an endangered species since 1976.

The U.S. Fish and Wildlife Service began reintroducing wolves into Arizona and New Mexico in 1998. Today, the population totals 83 in the two states.

Proponents of the bill say the reintroduction of wolves is endangering livestock and hurting ranchers’ livelihood.

Eva Sargent, Southwest program director with the Defenders of Wildlife, said the bill violates federal law and ranchers should use different approaches to coping with wolves.

“There’s a lot of proven keep wolves away and to move cattle away from active den sites," she argued. "There’s special fencing techniques. There’s a lot of ways and there are a lot of ranchers that are starting to use these techniques. So it’s a myth that ranching and wolves can’t coexist. It just takes a little extra work, a little extra thought.”

None of the bills sponsors were available for comment.

The Arizona House of Representatives still has to cast a final vote on the bill. It was already approved by the Senate.