Average temperatures in the winter range from highs of about 54 to lows near 40 degrees with an occasional frost. Annual rainfall averages near 25 inches per season, falling predominantly in the winter months.

The community was officially recognized as “Granite Bay” in 1987. As an unincorporated community, the Placer County Board of Supervisors is the local governing body, and a local Municipal Advisory Council provides input and advice to the Supervisors.

Granite Bay’s roots lead back to the early 1850’s, when gold miners first settled the banks of the American River. According to retired Park Ranger Dave McGrath there were 37 gold mining settlements along both sides of the River.

In its earliest beginnings, it was known as “Granite Bar”, a small mining camp just below Horseshoe Bar. The North Fork Ditch, built by the Natoma Company between 1852 and 1954, not only allowed miners to surface mine gold, it continued to supply water to the area and attracted settlers who planted olive and almond orchards. When the lake is low you can still find rows of stumps straight out from the Granite Bay boat launch ramp. Remains of the ditch can still be seen in places along the trail leading up the lake from Horseshoe Bar and along the water’s edge above the dam at low lake level. The sides of the ditch were concreted in 1925, which has helped to preserve its visibility.

Vivian Rasmussen recalled that what was is now called Auburn-Folsom Road was originally called Auburn-Sacramento Road. The road was built in 1850 to allow miners to travel back and forth with supplies. Whiskey Bar, Horseshoe Bar, and Rattlesnake Bar Roads were all established to connect the various settlements to the bar or to the main road. Granite Bar, later to be known as Granite Bay was named for the granite rock quarried from its banks and used as rip-rap in the wing dams of Folsom Dam.