THURMONT, Md. — Off a winding road in the Catoctin Mountains, rustic cabins with names like Dogwood and Birch border a stream where local lore has it that Herbert Hoover and Dwight D. Eisenhower once fished. The sprawling property, known as Trout Run, was used in the series “The West Wing” as a stand-in for Camp David, the presidential retreat just seven miles away.

Soon, the local council will vote on whether Trout Run should be on the register of historic places of Frederick County, Md., a seemingly simple decision about preservation that has turned into a strange fight about what the property might become.

Since 2013, Trout Run has been owned by the real estate arm of the Church of Scientology. Now Narconon, a drug-treatment program with ties to the church, wants to turn the property into a group home for recovering addicts. Zoning laws would normally prohibit that use in this location, but Narconon found a loophole in a local ordinance intended to encourage the reuse of historic properties.

If Trout Run, which is currently unoccupied, is added to the county’s list of historic places, Narconon could open a drug-treatment facility there. As a result, residents who do not want such a site in their backyard are doing the opposite of what locals often do with potential landmarks: They are trying to convince the county council that Trout Run, despite appearances and presidential connections, is not all that historic.