The Vineyard Conservation Society is gathering final approvals for a conservation restriction in Chilmark more than 20 years in the making. The town selectmen unanimously approved the deal this week, clearing the way for one final signature from the state office of Energy and Environmental Affairs.

The 7.1-acre property at 10 Eben’s Way includes stone walls, meadows and two houses. In her will, longtime Islander Thelma Cossutta, who died in 2013, donated the property to VCS and said the society could resell it, subject to a conservation restriction. The property is now listed for sale at $1.1 million.

“We are at the end of a 23-year process,” VCS executive director Brendan O’Neill told the selectmen at their meeting Tuesday. VCS will own the property, at least temporarily, while the town manages the restriction. Mr. O’Neill expected the deed to be registered by the end of the summer.

Ms. Cossutta, a native of Portland, Ore., who moved to the Island full-time in the 1970s, began negotiating with VCS in 1992. The basic terms of the restriction were in place by 1996. Over the last three years, VCS has been working with the Cossutta estate to obtain local and state approval. The restriction prohibits further subdivision and most development on the property in perpetuity.

“The main message that we want to reiterate is our gratitude to the Cossutta family,” Mr. O’Neill said by phone on Wednesday. He said it was somewhat unusual for VCS to receive property in a will. The group holds about 800 acres of conservation land throughout the Island, but its primary focus is environmental advocacy.

The Cossutta property abuts two other protected areas — a Martha’s Vineyard Land Bank property to the east and town-owned conservation land to the north and west. “It helps complete a foothold of conservation in this part of Chilmark.” Mr. O’Neill said.

The entire property is being sold, including a single-story passive-solar house built in the 1980s, and a smaller guest house. The restriction allows for both houses to be repaired, removed or replaced. They may also be expanded, but only up to 25 per cent of their original footprint. The 1,621-square-foot main house is “a fixer-upper for sure,” Mr. O’Neill said.

Future owners could develop accessory apartments for family members and caregivers, as regulated by the town’s accessory housing bylaw, passed in April, but those buildings would have to go where the existing houses stand. “It would be great if a new owner might want to exercise that opportunity,” Mr. O’Neill said.

In other business Tuesday, the selectmen approved several amendments to the town’s homesite guidelines, in light of questions that arose during a housing lottery last year. Among other things, the changes clarify the application and appeals processes, and raise an income threshold from $50,000 to $75,000.

The selectmen also approved the appointment of Tri-Town Ambulance deputy chief Ben Retmier as acting chief, following the resignation of Paul Wilkins in June. The Tri-Town Ambulance committee had voted July 1 to recommend that Mr. Retmier fill the role. Selectmen expected the hiring process to begin in September.

Shellfish constable Isaiah Scheffer reported a mysterious absence of eelgrass in Quitsa Pond this year, which would mean less habitat for young shellfish. An expert from the Environmental Protection Agency was expected to investigate the area this week. Selectmen Jonathan Mayhew was perplexed, noting that the eelgrass in Menemsha Pond is abundant this year.

The selectmen unanimously appointed Will Reich as assistant shellfish constable, a seasonal position with variable hours. But in light of strong shellfish yields and increasing off-season and weekend duties, the selectmen will consider expanding the position, possibly asking voters to appropriate funds.

The meeting included a lengthy discussion about how West Tisbury’s potential withdrawal from the up-Island school district might affect Chilmark. Up-Island school committee member Robert Lionette pointed out, among other things, that even if West Tisbury drops out, Chilmark and Aquinnah could benefit financially from a two-town agreement.

Selectman Bill Rossi said the town finance committee is already considering a “plan B” in case West Tisbury leaves the district. “We need to determine our costs,” he said. Mr. Lionette said that additional “forensic work” would be required to determine how Chilmark School affects the district as a whole.

Some argue that eliminating the position of the Chilmark School principal could reduce the overall cost to the district. Mr. Rossi agreed the topic was worthy of discussion. But selectman Warren Doty worried that losing the principal would diminish the Chilmark School’s role in the district.

“Over and over again, we come to a very generous education budget and the voters all vote, unanimously, yes,” Mr. Doty said. “I think it’s clear that Chilmark has said: We want good education and we want the Chilmark School.”

A study committee in West Tisbury to explore the possibility of leaving the district is still taking shape. West Tisbury town administrator Jennifer Rand said Thursday that she hopes the committee will begin meeting this summer.