The columns are of concrete, the steps leading to the entrance are of granite, and there is marble detailing on the building walls.

The back of the building, where mail is processed, is separated from the public space by a service area.

[2] Great Barrington's position as a major economic center of southern Berkshire County since the early 19th century means it has had postal service since 1797.

Until the construction of this building, those services were always provided in leased commercial spaces, private residences of the postmaster, and the local deed registry.

This building's neo-Classical design is the result of Rich's alteration of a standard plan.