Johannesburg was founded to support mining operations at Randsburg. In addition to providing rail access, the region's first wells were operated by companies located in Johannesburg. During the first half of the 20th century, the Rand Mining District was the principal gold producing region of California. Activity centered on the Yellow Aster Mine, discovered in 1894. In 1919, the Rand Silver Mine was discovered east of town on Red Mountain. The Rand Mine produced more silver than any mine in California.
