A federal judge plans to issue a ruling Friday deciding whether to delay the reintroduction of wolves in Colorado based on a legal challenge filed this week by ranchers.

Unless a court order puts the reintroduction on hold, state officials said during a hearing Thursday that they could be just days away from capturing wolves to bring to Colorado.

The Colorado Cattlemen’s Association and the Gunnison County Stockgrowers’ Association on Monday filed a federal lawsuit against Colorado Parks and Wildlife and the U.S. Fish and Wildlife Service. The lawsuit alleges that the government agencies violated the National Environmental Policy Act by failing to produce an environmental impact statement while renewing a cooperation agreement between the two agencies about conserving endangered species.

The lawsuit and subsequent filings by the livestock groups asked U.S. District Court Judge Regina Rodriguez to halt Colorado’s reintroduction efforts while the litigation proceeds.

Colorado Parks and Wildlife officials intended to release wolves in the state by Dec. 31, as mandated by Colorado voters through a 2020 ballot measure. Staff members from the state wildlife agency were planning on traveling Sunday to Oregon to capture wolves to bring to Colorado, said Lisa Reynolds, an attorney for Colorado Parks and Wildlife, during Thursday’s court hearing.

Plans call for the initial release to occur in Summit, Eagle or Grand counties. Ranchers are preparing but have expressed concern about the wolf reintroduction.

Rodriguez said the issue at hand was not whether it’s a good or bad idea to reintroduce wolves, but whether the government agencies violated the law by failing to conduct an environmental analysis while renewing the cooperation agreement.Several wildlife advocacy groups have entered the litigation.

“We’re confident the court will quickly dispose of this ridiculous case,” Collette Adkins, the carnivore conservation program director at the Center for Biological Diversity, said in a statement. “We’re fighting back to ensure the carefully planned wolf releases aren’t delayed by the livestock industry’s self-serving and meritless arguments.

“Colorado voters want wolves restored to their rightful place in the state’s ecosystems, which will greatly benefit from the return of these magnificent animals.”