BILLINGS, Mont. — Repeatedly stifled in efforts to transplant bighorn sheep in new locations in Montana over the past few years, the state’s wildlife commission chairman said it may be time to rethink the state’s conservation strategy for the popular big game species.

“I guess what I’m hearing is we don’t have any place in Montana to place sheep,” said Dan Vermillion, Fish and Wildlife Commission chairman, at the group’s last meeting.

“Not with the criteria we’ve established,” said John Vore, FWP’s game management bureau chief. “Much of our historic sheep habitat didn’t have domestic sheep.”

Vore said recently that he’s preparing a presentation for the commission that outlines the criteria for where sheep can be established and places that the department has already looked at that don’t meet those guidelines.

“We keep looking at areas and we’ve looked at many, many,” he said.

Under the state’s conservation plan — adopted in 2010 — FWP set a goal of creating five new huntable populations of bighorn sheep in the state by 2022. Yet time and again the department’s attempts to transplant wild sheep have been thwarted.

In 2013 a plan to transplant sheep to public land near Lewis and Clark Caverns was canceled after a Cardwell legislator and landowner said he was unaware of the proposal and introduced a bill to restrict future transplants. The bill died in committee and the transplant proposal was killed.

Later that year a proposal to put bighorns in the Bridger Mountains was delayed because of the nearby presence of domestic sheep, which can transmit certain bacteria to bighorn sheep that are lethal.

Then this year a transplant in the Madison Mountains was delayed to 2015 after an outbreak of pneumonia in the parent herd was detected.

Recently, a frustrated commission voted against the department’s proposal to transplant sheep to South Dakota as a way to thin certain herds and thereby lessen the chance of disease being spread by crowding, The Billings Gazette reported.

Increasing hunting permits to thin a herd is not as surgical, Vore told the commission, since the herds are sometimes inaccessible to hunters. Moving sheep from one herd to another is also dangerous since infections could be spread, Quentin Kujala, FWP’s wildlife management section chief, told the commission.

“It would be well advised for us to revisit the plan” at some point, Vore told the commissioners.

One of the authors of the state’s bighorn sheep plan disagrees that the plan is to blame. Now-retired FWP biologist Tom Carlsen, who sits on the Montana Wild Sheep Foundation board, said the plan’s scientific criteria give bighorn transplants “the best chance to be successful.”

“Quite frankly, I don’t think they’ve exhausted all of the (habitat) possibilities,” he said, pointing to the Tobacco Root and Snowy mountains as options.

Carlsen said FWP is too occupied with managing higher profile wildlife that draw too much of the department’s resources — animals like wolves, bison and the elk brucellosis issue. Consequently, bighorn sheep get less attention despite the fact that an annual auction of a Montana bighorn sheep tag brings in hundreds of thousands for sheep management. This year, the tag sold for $320,000. In 2013 it set a record at $480,000.

Hunters covet the restricted tags issued through a lottery for bighorn sheep in Montana, even though the chance of success low. In 2013, more than 19,500 Montana hunters applied for 230 bighorn sheep tags and more than 7,200 nonresidents tried for 21 tags.

“As director (Jeff) Hagener pointed out, we have the best bighorn sheep population in the lower 48,” Vore said. “There’s a reason we have the population we have and the quality rams we have.”

One thing Carlsen and FWP do agree on is that transplanting sheep to other states is the best way to reduce sheep herds to the ideal management levels. He said the commission’s decision not to move sheep out of state was “bad biology.”

“You’re putting those populations that are over objective at risk,” he said. “They are more susceptible to disease when they are at a high density.”

In the winter of 2009-10, more than 500 bighorn sheep died of disease in the greater Missoula area, with two of the four afflicted herds experiencing die-offs of 60 percent or more.

Carlsen said that following such widespread outbreaks of disease, bighorn lambs born to surviving ewes often die as the bacteria is passed on. He pointed to the Elkhorn Mountains, where he worked to establish a bighorn population, as an example. Eighty percent of the animals have succumbed to disease, devastating the once-thriving herd to the point where only 20 to 30 bighorns still survive.

“What I’d like to see them do, and they are doing it in other states, is go in and remove all of the animals and start over,” Carlsen said. “You can’t augment a herd that’s carrying disease.”

In the Elkhorn Mountains, a huntable herd was established in less than 10 years, Carlsen noted.

“Why fiddle around and wait for a potential recovery that never happens,” he said. “And that’s another way to use in-state sheep.”