The Mariposa County Courthouse is the oldest courthouse in California and the oldest one west of the Rocky Mountains that is still being used. Since 1851, when Mariposa was a vibrant trading center for miners, the courthouse was the place where landmark mining laws were tried, and consequently, set legal precedent for federal mining law.
The four walls enclosing the historic courtroom on the second floor vibrated with the sounds of Colonel John Fremont trying his case for ownership of the Mexican land grant Rancho las Mariposas and win. Attorneys argued cases of murder, divorce, robbery, mining rights, fraud and property disputes. Mariposa’s historic courthouse served nearly one-fifth of all California residents, since the county at that time also encompassed the current counties of Merced, Mono, San Benito, Madera, Fresno, Kings, Tulare, Inyo, Kern and parts of Ventura.
The Greek Revival style courthouse was constructed in 1854, using lumber from nearby forests. The building is constructed by using the interlocking mortise and tenon construction method and held in place with wooden pegs. The original chairs and benches are still being used inside the simply decorated courtroom on the second floor. Modern conveniences, such as electric lights, computers and climate control systems are hidden from view. The tower clock still in work order has three weights that need to be reset every three days to keep it running.
The courthouse is located at 10th and Bullion streets in the city of Mariposa.
Information about Mariposa County Courthouse Historic District is also located at Mariposa County Courthouse.
The wonders of the Yosemite Valley’s granite cliffs lie in eastern Mariposa County. The small settlements in the western foothills of the country sprang up during the Gold Rush. The people in these early mining towns made many decisions affecting statewide mining law.