BILLINGS, Mont. (AP) — Yellowstone National Park's superintendent said Thursday he's being forced out as a "punitive action" following disagreements with the Trump administration over how many bison the park can sustain, a longstanding source of conflict between park officials and ranchers in neighboring Montana.

Superintendent Dan Wenk last week announced he intended to retire March 30, 2019, after being offered a transfer he didn't want to take.

He said was informed this week by National Park Service Acting Director Paul "Dan" Smith that a new superintendent will be in place in August and that he will be gone by then.

"I feel this is a punitive action but I don't know for sure," Wenk told The Associated Press. He wasn't given a reason and said the only dispute he's had with Interior Secretary Ryan Zinke was over bison.

Ranchers in neighboring Montana have long sought reductions in Yellowstone's bison numbers because of worries that they could spread the disease brucellosis to cattle and compete with livestock for grazing space outside the park.

Wenk and park biologists have said the current population of more than 4,000 bison is sustainable. But Zinke and his staff have said the number is too high, Wenk said, and raised concerns that areas of the park such as the scenic Lamar Valley are being overgrazed.

Zinke is a former Montana congressman. His close attention to projects back home has stirred speculation he has future political ambitions in the state.

Zinke spokeswoman Heather Swift declined to comment directly on Wenk's assertions or the issue of bison management. She referred a reporter to a previously issued statement that said President Donald Trump had ordered a reorganization of the federal government and that Zinke "has been absolutely out front on that issue."

"We're not a livestock operation. We're managing a national park with natural systems," Wenk said. "We do not believe the bison population level is too high or that any scientific studies would substantiate that."

Wenk spent more than four decades with the National Park Service and seven years in Yellowstone.

Last year, members of the park's maintenance department were disciplined after an investigation found female employees were subjected to sexual harassment and other problems.

The scandal echoed problems that surfaced in recent years in other national parks and in some instances prompted personnel changes, but Wenk said that was never brought up in the discussions about transferring him to a new post.

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