Middle Bar was founded in 1850 by Englishminers. A mine in the area produced gold quartz. In 1851, the Middle Bar Bridge was built over the Mokelumne River to handle the large amount of gold seekers coming through the area. The following years, 1852, a flood washed the bridge away. Another bridge was built with claims stating it was high enough it would not get washed away. It was finished in November, 1852, and cost $25,000 to build. It stood for approximately ten years until another flood dislocated the bridge. After the first gold rush, the area experienced a second round of increased population in the 1920s during a smaller mining rush. Eventually, the homes of Middle Bar were purchased by the East Bay Municipal Utility District. The company had built the Pardee Dam, six miles away.