At the main entrance to the building is mounted a bronze plaque indicating that the building was constructed in 1912. This is true; however, it was not ready for occupancy until 1913. 110 years old this year (2023), the courthouse has been in continuous use for those 110years..
Granite County Courthouse
The first permanent home for Granite County offices was completed in 1913. Prominent Montana architects John Link and Charles Haire designed the building. Its cut stonework is, appropriately, made of Montana granite. Granite County commissioners paid the Gagnon and Company construction firm $49,000 for completion of this elegant brick county courthouse. Look for the inscription “Granite Co.” in the keystone above the entry arch.
From the NRHP Plaque
Following the establishment of Granite County in 1893 and Philipsburg as the county seat, county commissioners hired the state’s preeminent architectural firm to design this 3½-story Neoclassical style civic building.
The Gagnon and Company construction firm undertook the project for $49,000. The ashlar stone courthouse is built of Montana granite and has a central, shallow dome with a lantern and fenestrated drum. A giant Doric pedimented entrance faces west, and there is a semi-circular transom above the main doors that contains a more recent art glass window. In the plaque above the entry arch are inscribed the words, “Granite Co.”
From Vernacular Architecture of Montana