The Massachusetts Supreme Judicial Court last week upheld the town of Aquinnah and the Martha’s Vineyard Commission in a key leg of a complicated and long-running property rights case that will ultimately decide whether a large swath of rare coastal heathland along Moshup Trail remains forever wild or is opened up to private development.

A long-running effort by an Aquinnah property owner to build a house on a lot off Moshup Trail was blocked by the town planning board plan review committee this week, which found the lot lacks adequate road frontage under new zoning rules adopted by the town eight months ago.

After a series of public hearings that began in October, the committee voted 7-0 on Tuesday night to deny a special permit for James Decoulos to build on the two-plus-acre property.