CONCORD, N.H. — The state is evaluating whether a 16-acre patch of old red spruce trees on the side of Mount Sunapee is a pristine enough patch of land to require legal protection that could derail a ski area’s contentious and long-debated proposal to expand over state park lands.

In a report delivered to the state’s Department of Resources and Economic Development and provided to The Associated Press, the state’s Natural Heritage Bureau said it confirmed the existence of the stand of mostly red spruce trees, some of which were over 170 years old. The land, part of Mount Sunapee State Park, showed no signs of logging or other human interference and the bureau deemed the spruce trees part of an “exemplary forest.”

That word – exemplary – is key. State law says: “To the extent possible actions funded or carried out by state agencies shall not jeopardize the continued existence of any protected plant species or exemplary natural community.”

Jeffrey Rose, the DRED commissioner, said he ordered the re-evaluation to get the most updated information as his department considers whether to allow expansion. He said the trees – in an area called Polygon D – were mature, not old growth, but they are still determining if they’re exemplary.

Rose said there’s no timeline for a final decision from DRED. Another round of public comment will be solicited before a final recommendation is made.

Jay Gamble, vice president and general manager of the ski area, was confident the trees would not stall expansion plans.

“I can tell you unequivocally, there is no old growth forest in that area,” Gamble said Friday. “This is a fragmented area that is part of the larger area that they are describing.”

The Sunapee Difference, the company that operates the Mount Sunapee Resort in the western part of the state, has been trying to expand for nearly two decades. The company says it wants to expand the ski mountain by adding a lift and four trails, but opponents worry that the company will build condominiums on the private land and connect them to the ski mountain.

The trees cited by the heritage bureau are on parkland leased by Sunapee in 1998 with an eye toward expansion.

These kinds of old growth forests are fairly rare in southern New Hampshire and are more likely found in, and north of, the White Mountains. They’re important ecologically because they are home to a far more diverse set of plants and animals than found in managed forests. Large, intact forest systems are also more resistant to effects brought on by things like insects, disease and human interference.

“The Natural Heritage report affirms what hikers and backcountry enthusiasts have enjoyed and experienced for decades,” said Catherine Bushueff, a volunteer with Friends of Mount Sunapee, a group that opposes the development proposal. “Mount Sunapee State Park protects some of the most precious and important natural forest in New Hampshire.”

The group is calling on Gov. Maggie Hassan to direct DRED to end its consideration of the expansion and ask the resort to limits future projects to areas of the park already disturbed.

William Hinkle, a spokesman for Hassan, said she is waiting for DRED’s final recommendation.