In a lawsuit filed Wednesday, the Center for Biological Diversity and two other groups say it's premature to delist the animal with only about 80 adult wolves living in the state.
The Oregon Fish and Wildlife Commission stripped wolves of their endangered status in November, after state biologists said the species won't go extinct.
But some independent scientists disagree with that conclusion. According to wolf advocates, the Commission failed to follow the best available science and its population viability analysis for the wolves was flawed.
"The commission's decision to delist wolves is plain political kowtowing to the livestock industry. This decision was not based in science, it was not based on Oregon's conservation values," said Noah Greenwald, Endangered Species Program director at the Center.
Oregon Fish and Wildlife spokeswoman Michelle Dennehy declined to comment on the lawsuit. But she said "ODFW is confident the department followed statutory and legal requirements in its process and that the Commission acted legally when it delisted wolves form the state ESA."
Dennehy said the Commission's decision to delist wolves was based on their rapidly expanding range in Oregon, their growing population, the stability of their habitat and the fact that "over-utilization" of wolves isn't likely to occur.
Delisting the animal doesn't mean all protections are gone, Dennehy said. A state management plan continues to tightly regulate when a wolf can be killed.
But environmental groups worry that more lethal measures could be allowed in the future. An upcoming wolf plan review could also lead to changes in protections.
The decision to delist wolves statewide would have the biggest impact on wolves in eastern Oregon. They were taken off the federal endangered list four years ago after Congress used a budget rider attached to a spending bill, which also removed the animal from the list in the northern Rockies, eastern Washington and parts of Utah.
But the environmental groups said state protection is also needed for the western part of the state because federal officials are now proposing to strip wolves of federal protections in most of the lower 48, including in western Oregon.
Research shows Oregon could support approximately 1,450 wolves.