By the start of the 20th century, it was an important regional trading center for western Montana, northern Idaho, and eastern Washington.

[2] Because of the growing population and the subsequent need for services, Missoula was selected as the location for a federal building.

The Supervising Architect of the Treasury, James Knox Taylor, designed the new building, and construction commenced in January 1911.

In 1927, James A. Wetmore, acting supervising architect of the U.S. Treasury Department, designed an extension and an annex to the original building to house judicial functions.

Thirteen firefighters, who were members of an elite U.S. Forest Service team known as the smokejumpers, died when the blaze blocked their escape route.

The 1952 film Red Skies of Montana was based on the Mann Gulch fire, and one of the scenes features the Federal Building, U.S. Post Office and Courthouse.

The Federal Building, U.S. Post Office and Courthouse is located on a block bounded by Broadway, Pine, and Pattee streets, near the central business area.

The foundation is clad in smooth-faced granite, and limestone ashlar covers the principal facade and side elevations.

The upper stories are defined by a series of two-story pilasters (attached columns) that have Corinthian capi-tals with ornate acanthus leaf patterns.

[2] The post office lobby, which is part of the original building, retains many historic features and finishes.

The floor is covered with panels of alternating light and dark marble that are arranged on a 45-degree angle with the lobby walls.

The walls are trimmed in dark gray marble at the base, while a molded wood cornice with a dentil course tops the space.