An unusual plan by a private landowner to build and pay for a 619-foot wooden walkway across property owned by the Martha's Vineyard Land Bank will go before the Chilmark conservation commission on Wednesday.

If the conservation commission allows it, the walkway will link two private properties by crossing 2.5 acres of wetland owned by the land bank. Owned through a real estate trust by actor and screenwriter Larry David, who is a summer resident of Chilmark, the properties are located on the south side of North Road just beyond the Captain Flanders House.

The public hearing begins at 2:30 p.m. at the town hall. The conservation commission will decide whether to allow the proposal under state and local wetlands regulations.

In exchange for permission to build the walkway, representatives of the David trusts have offered the land bank two trail easements on Mr. David's properties.

The plan has drawn some criticism from neighbors who question whether the walkway will serve more as a private path than a public way.

Jackie Mendez-Diez, whose property abuts the wetland on the east, said the land bank plan to allow a private property owner to build on public land goes against its charter.

"They never notified the abutters that they were going to build this thing," she said yesterday. "It just seems like a deal between the land bank and the property owners. I am not against the use of land for public access, but I object to the land bank's methods in this case."

Land bank executive director James Lengyel said the agency has never had a policy of notifying neighbors of changes to a property management plan.

"We just don't do that, it's not custom," he said. "Where else has the land bank done this on the Island? This is something that benefits the property owners, benefits the land bank and most of all, benefits the public. In the land bank's opinion, it is a win-win for everybody."

The proposal calls for a long, winding walkway, including 205 feet of elevated platform, 167 feet of duck board, 139 feet of ground path, 34 feet of stairs, 26 feet of terraced walkway, a 48-foot bridge and a four-square-foot platform. With the easements at both ends, Mr. Lengyel said the walkway would create a new trail with a potential link to the Peaked Hill Reservation, another land bank property.

The builders are Chilmark Cottage Craft, a family company headed by Frank and Peter Dunkl, which uses natural, untreated black locust wood.

Chilmark conservation officer Russell Walton said on Tuesday he found no reason for the commission to reject the plans, which he said appeared to be environmentally responsible.

Michael Halbreich, a trustee of the Chilmark Aerie Realty Trust, filed a notice of intent with the Massachusetts Department of Environmental Protection to build the walkway two weeks ago. He dismissed any notion that it would be created for anything other than public use.

"What we are utilizing is for the benefit of the public. Offering easements on the properties and the many hundreds of feet of trail it brings with it is, if anything, a burden to the properties, not a benefit to them.

"We want to make sure it fits in with the environment, but our interest is putting down whatever the conservation committee and land bank require for the public to use the property," he said. "The least amount of intrusion on the wetlands is the exact goal we all have in mind.

"We're not going to be putting up no trespassing signs," he added.

The circumstances surrounding the land bank's ownership of the property are complicated and go back two years.

The 2.5-acre parcel is part of 21.9 acres the land bank purchased in December of 2002 from a trust created by June Brehm Tabor. The remaining 19.4 acres lie further east, across Aerie Road, and connect to the land bank's 114.9-acre Peaked Hill Reservation.

In negotiating the deal, Ms. Tabor and the land bank agreed that there will be no public access to the property until she dies or vacates her property, which abuts the eastern edge of the 19.4-acre lot. Public access to the land, therefore, is currently not allowed.

"That is why this will essentially be a private access path between the two private properties until it is open to the public, and who knows how long that will be," Ms. Mendez-Diez said.

The land bank never issued a public announcement about the Tabor property purchase.

In a telephone conversation yesterday, Ms. Tabor said she might consider opening the small parcel of land to the public if a walkway was constructed.

"I'm interested in whatever is right for the land," she said.

"It is, at the most, a temporary measure," said Mr. Lengyel. "Even if it is private at first, the public is, in the long run, gaining access to a beautiful piece of property, and the trail easements provided by the private owners only enhance that. The offer of a footbridge would not, by itself, be appealing to the land bank. The motivating factor for us was the trail easements. They give us more options for future trails."

Mr. Lengyel said private contributions to land bank properties are not unusual. For example, he said, the land bank sometimes makes arrangements with private contractors to clear trees and brush from a property without charge in exchange for the discarded wood. Tenants in preexisting houses on land bank properties have paid for renovations to the buildings, he said.

He admitted that he couldn't recall a private citizen paying to build a structure like a bridge on land bank property.

"It's not an unprecedented act of private philanthropy," he said, "but it is a unique situation." He said the walkway becomes the property of the land bank upon completion.

"There are so many neighborhoods where a small trail easement would make a difference," Mr. Lengyel said. "So we are very pleased that this neighbor embraced this public goal, and we remain committed that some day, people will be able to hike from Menemsha to East Chop."