Organized in 1864, Nye County was named in honor of Nevada Territory's governor, and first senator, James Warren Nye. Originally the seat of government was situated in Ione, but the state legislature moved it to Belmont in 1867. The county did not approve plans for a permanent courthouse until 1875, when commissioners accepted the design of J. K. Winchell. They granted a $22,000 construction contract to J. T. Benham.
The Italianate style courthouse exhibits corner pilasters, six brick chimneys, a bracketed cornice, and a Tuscan cupola. The community celebrated the completion of the new courthouse on the nation's centennial, July 4, 1876.
At the turn of the century, Belmont's struggling economy prompted a county seat shift to Tonopah, which was in the midst of a mineral-mining boom. The county awarded a $28,000 contract to the Continental Construction Company for a structure designed by J. C. Robertson. The Tonopah Mining Company donated land for the project.
Supervised by local artisan E. E. Burdock, the two-story building of ashlar and concrete was completed within a year. With its rounded arches supported by clustered columns, the design exhibits substantial Romanesque details that are rare in Nevada. The structure's dome sits atop a moderately pitched pyramidal roof, and a molded cornice accented with dentils is positioned among the eaves.
In 1907, the county added a two-story jailhouse of the same ashlar stone composition, also designed by Robertson. Diverging from the original Romanesque style, three additions to the structure in the 1960s included new wings made of concrete block with vertically grouped windows, and a flat roof. A porch of steel and glass was added in recent years. The Belmont courthouse and surrounding property now serve as a park.