The threat from development might be small, minute in most cases.

But with a handful of private owners still with property on Masonboro Island, there’s always the chance that someone’s dream about living at the ocean could involve building on the 8-mile-long undeveloped island.

This summer, officials hope to reduce that possibility just a little bit more by purchasing nearly 23 acres, the largest privately held parcel left on the island, near Masonboro’s southern tip.

“This is wonderful because every little bit helps,” said Camilla Herlevich, executive director of the N.C. Coastal Land Trust, which spearheads the effort to take the island’s private lands public.

For decades, state and local officials have tried to join the hodgepodge of private lots with the vast majority of the nearly 5,000-acre island that’s already part of the state-run National Estuarine Research Reserve.

But as the big parcels have become protected, it’s become harder and harder to get the remaining private lands under state stewardship.

Partly that’s because some people don’t want to sell, even if they can’t do much with their oceanfront property.

But also many of the parcels, whose ownership dates back to colonial days, are now owned by numerous heirs. Getting them all to agree to sell – as required by law – is difficult.

That’s what makes the impending purchase of Susan McMillan’s 23 acres so special.

“It would be among the larger transfers in recent times,” said Bill Raney, a Wilmington attorney who worked with the Society for Masonboro Island before it merged with the Land Trust in 2003.

According to the state property office, the government would pay McMillan $3,648 per acre for a total of $85,000.

That’s dirt cheap for barrier island property.

But that’s because it would probably be next to impossible to win planning permission to build anything of significance on the island, which has no infrastructure.

A lot of the McMillan land is also marsh, with only a small amount of the 23 acres potentially buildable uplands.

But Raney said that’s not really the point of getting the property under state ownership.

“If nothing else, private ownership out there could disrupt research and educational projects as well as recreational activities,” he said, noting that an owner could conceivably fence off his property or simply place “No Trespassing” signs around it. “So it is important that it be in public ownership even if the owner didn’t have any intention of building anything out there.”

McMillan, who lives in Fayetteville, couldn’t be reached for comment this week.

Hope Sutton, who manages the state’s southern reserves sites for the N.C. Division of Coastal Management, said the presence of private property scattered around the island hasn’t interfered with the management of the natural site.

But everyone agrees that the only way to truly make sure that Masonboro, which only became an island in the 1950s after Carolina Beach Inlet was blasted open, remains an undeveloped escape from the urban jungle on the other side of the Intracoastal Waterway is to secure all of the remaining private property.

“The real threat of development out there is probably gone,” said Herlevich, since only about 50 acres will remain in private hands after the McMillan transfer. “But it’s still good to try and make that possibility as remote as possible.”

Gareth McGrath: 343-2384

gareth.mcgrath@starnewsonline.com