Sonora, California is the county seat of Tuolumne County, California. The city population was 4,903 during the 2010 Census, up from 4,423 during the 2000 Census. Sonora is the only incorporated community in Tuolumne County. The area economy was historically based on the mining and timber industries, but now relies on tourism.[13] One of two active lumber mills in Tuolumne County was shut down in 2009, but reopened in July 2011.[14] * Sonora Youth Sports