MINERVA, N.Y. — A 250-foot waterfall, one of the tallest in the Northeast, tumbles over giant slabs of marble. A chain of 13 crystalline lakes and ponds teems with bass and lake trout. A 10-mile stretch of the Hudson River gorge winds through dense stands of hemlock, white pine and red maple.

These natural features make up the more than 21,000 acres of the Adirondacks that were recently purchased by New York State from the Nature Conservancy, a nonprofit organization. By October, the land will be entirely opened to the public for the first time in more than a century. It is now part of the forest preserve, allowing visitors to experience a resplendent landscape in the heart of the six-million-acre state park.

But while environmentalists, town officials, paddlers, boaters, hikers and snowmobilers have embraced the pristine wilderness, they now find themselves in a tug of war over how the land should be enjoyed. Should it be reserved for quiet recreation like canoeing, rafting and hiking? Or should it also be open to cars, motorboats and Jet Skis? It is a debate that has long torn at the Adirondacks, and it revolves around an invisible entity: noise.

“It is a spectacular resource,” said Joseph Martens, commissioner of the state’s Department of Environmental Conservation, of the new forest preserve lands. “The challenge is to find a way to make that resource accessible to a wide variety of people — meaning the elderly, disabled and families — but that doesn’t damage the resource itself. It’s a balancing act. You have to respect both objectives.”