John Norbeck, head of the state’s award-winning park system, said the Corbett administration forced his resignation last week because of “philosophical differences,” including his opposition to commercial timbering, mining and Marcellus Shale gas drilling in the parks.

His departure comes on the heels of recent criticism of the state Department of Conservation and Natural Resources by Paulette Viola, a longtime Citizens Advisory Committee member, about its lack of transparency on resource extraction issues and amid reports of widespread morale problems.

In a phone interview from his home Sunday, Mr. Norbeck, 56, said he received a termination letter from the state’s human resources office on Oct. 1, informing him that his last day of work would be Friday, Oct. 5, but “if he wanted to tender his resignation it would be considered.”

On Wednesday he agreed to resign and asked for, and was granted, a two-week extension, through Oct. 19, to prepare a transition document for a new parks director.

Mr. Norbeck said he wasn’t told why the administration wanted him out. The closest anyone came, he said, was when Adam Gingrich, an executive assistant to DCNR Secretary Richard J. Allan, said the “administration has decided to go in a different direction.”

Although Mr. Norbeck said he didn’t know of any one issue that caused the administration to sour on him, he cited several on which he differed with it.

He said Ellen Ferretti, appointed by the Corbett administration as DCNR deputy secretary for parks and forestry in June 2011, discussed starting commercial timbering operations in the state parks, but he told her proposing such a program would be “walking into a public buzz saw” and the revenue that could be generated wouldn’t be worth it.

Another involved a proposal by Amerikohl Mining Inc. to mine limestone under the 13,625-acre Laurel Ridge State Park in Somerset County. That proposal, which has not been publicly reported, was denied twice by the parks bureau, but Amerikohl has a meeting scheduled with DCNR officials in the coming weeks to ask again, Mr. Norbeck said.

He said state park rules clearly prohibit mining on parkland. John Stilley, Amerikohl’s chief executive officer, said the company informally approached DCNR about allowing mining of the Loyalhanna limestone seam at a depth of about 200 feet. Such an operation would be an extension of Amerikohl’s Jim Mountain Quarry, an all-surface operation that now is within 300 feet of the state park boundary.

“The limestone belongs to the state park but we made an informal request to see if we can generate some income for the park,’ said Mr. Stilley, who along with relatives contributed more than $32,000 to Mr. Corbett’s political campaigns but denied he is trying to exert any political influence.

Mr. Norbeck, who has six years of outstanding job evaluations in his personnel file and was known to regularly work 50 or 60 hours a week, said he was angry about the administration’s decision to get rid of him.

“… we were doing great stuff in the state’s parks,” he said. “I’ve talked to hundreds of people in the last week, and they are scared about what’s going to happen to the department and the parks bureau.

“Morale is seriously low and there’s concern about the lack of leadership coming out of the administration.”

Mr. Norbeck worked in Maryland’s state parks system for 29 years before he was appointed to head Pennsylvania’s parks in 2006 by Gov. Ed Rendell. Under his stewardship, the state’s system of 117 parks won the 2009-11 National Gold Medal for Excellence in Park and Recreation Management awarded by the American Academy for Park and Recreation Administration and the National Recreation and Park Association.

During Mr. Norbeck’s tenure, the Bureau of Parks, working with a shrinking staff, has seen park visitation increase from 35 million to 38 million a year, and income from rentals and services jump from $13 million in 2006 to $21.5 million last year.

Jeff Schmidt, executive director of the Sierra Club in Pennsylvania, called Mr. Norbeck “one of Pennsylvania’s top professional conservationists.”

“Anyone who knows John Norbeck knows his priority has always been to protect our precious natural resources, which are owned by the people of Pennsylvania,” Mr. Schmidt said.

Christina Novak, a DCNR spokeswoman, declined to discuss the resignation because it’s a personnel matter.

Mr. Norbeck’s resignation is not the first sign the Corbett administration’s natural resources management policies are creating turmoil at the DCNR. Last month Ms. Viola, who served 19 years on the DCNR Citizens Advisory Council, quit, saying the administration was ignoring citizen input, had thwarted council efforts to study drilling policy on public lands and had cut the council’s $200,000 annual budget by 90 percent.

But Mr. Allan doesn’t agree.

“DCNR will continue to support the work of the council, and we value its advice and recommendations,” he said. “We look forward to working with the new council appointee and will welcome a fresh perspective.”