Rocklin is a city in Placer County, California, located approximately 22 miles (35 km) from Sacramento, California, and about 6.1 miles (9.8 km) northeast of Roseville in the Sacramento metropolitan area. Besides Roseville, it shares borders with Granite Bay, Loomis and Lincoln. As of the 2010 census, Rocklin's population was 56,974. The California Department of Finance placed the 2019 population at 68,823.
Prior to the California Gold Rush, the Nisenan Maidu occupied both permanent villages and temporary summer shelters along the rivers and streams which miners sifted, sluiced, dredged and dammed to remove the gold. Explorer Jedediah Smith and a large party of American fur trappers crossed the Sacramento Valley in late April 1827. The group saw many Maidu villages along the river banks. Deprived of traditional foodstuffs, homesites and hunting grounds by the emigrants, the Nisenan were among the earliest California Indian tribes to disappear.
During the 1850s, miners sluiced streams and rivers including Secret Ravine which runs through Rocklin. The piles of dredger tailings is still obvious today, between Roseville and Loomis southeast of Interstate 80. Secret Ravine at the area now at the intersection of Ruhkala Road and Pacific Street was later mined for granite, some of which was used as the base course of the California Capitol Building in Sacramento, although the earliest recorded use of the rock was for Fort Mason at San Francisco in 1855. The granite was hauled out by ox carts before the arrival of the railroad many years later.
In 1860, the U.S. Census counted 440 residents in the area of Secret Ravine, of which approximately 16% had been born in Ireland and the majority of whom worked as miners.