Now inundated by Millerton Lake, Fort Miller was established in 1852 as a temporary headquarters for the Commissioners during the latter part of the Mariposa Indian War. The peace treaty was signed there April 29, 1851. The first recorded religious services in the Fresno area were performed here on October 21, 1855 by Right Reverend William Ingraham Kip, first Protestant Episcopal Bishop of California. The village of Rootville grew into the town of Millerton and became the first seat of Fresno County in 1856.
The first “permanent” Fresno County Courthouse established in 1856. Millerton served as County Seat until 1874 when government functions were transferred to Fresno. In 1940 the US government began construction of Friant Dam which required the removal of the former courthouse. The tedious process of taking the building down brick by brick began. In 1944 as Millerton Lake flooded the former Millerton town site the courthouse began its new life as a museum on Mariner’s Point overlooking the new Lake and Dam.