Sonora is the county seat of Tuolumne County, California. The city population was 4,610 during the 2010 Census, an increase of 380 from the 4,230 counted during the 2000 Census. Sonora is the only incorporated community in Tuolumne County.
Founded by Mexican miners — many experienced ones from the state of Sonora, Mexico — during the California Gold Rush. Sonora was once a booming center of industry and trade in California's Mother Lode. Most of the gold that was removable with traditional mining techniques was quickly extracted, leaving miners to use more complex and expensive mining techniques to reach deep pockets of quartz and gold. Sonora as well as other mining towns of the era experienced economic hardship when the value of gold decreased. As easier accessible gold deposits dried up, businesses and miners realized extracting the gold cost more than it was worth. As "gold fever" died down, Sonora's size and population steadily decreased over the years.
A local museum serves to remind locals and visitors of the Gold Rush era and what Sonora was once like.
As detailed by novelist David Carkeet, in his memoir, Campus Sexpot, Sonora was fictionalized as "Wattsville", the setting of Dale Koby's cult/underground classic (also titled Campus Sexpot).