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.
Rocklin’s history is closely tied to the transcontinental railroad. In 1862, the Pacific Railroad Act granted the Central Pacific Railroad land near Secret Ravine. In 1864, the Central Pacific Railroad completed an extension of its track southwest from Newcastle to Secret Ravine. It named the area Rocklin after its granite quarry, and used the site a refueling and water stop. The Central Pacific built a roundhouse in 1867. The transcontinental railroad was completed in 1869, significantly increasing railroad traffic through the town. According to the 1870 census, Rocklin had grown to 542 residents, and the majority of Irish immigrants had foregone mining and were working for the railroad. In 1906 the Central Pacific moved its facility from Rocklin to Roseville, where more land was available for expansion. The site in Roseville has remained in continuous use since. As of August 2014, it is the largest rail facility near the US West Coast.
The population was spread out with 15,613 people (27.4%) under the age of 18, 5,306 people (9.3%) aged 18 to 24, 15,159 people (26.6%) aged 25 to 44, 14,668 people (25.7%) aged 45 to 64, and 6,228 people (10.9%) who were 65 years of age or older. The median age was 36.7 years. For every 100 females there were 94.0 males. For every 100 females age 18 and over, there were 90.4 males.
There were 22,010 housing units at an average density of 1,123.3 per square mile (433.7/km²), of which 13,797 (66.3%) were owner-occupied, and 7,003 (33.7%) were occupied by renters. The homeowner vacancy rate was 2.5%; the rental vacancy rate was 7.3%. 39,295 people (69.0% of the population) lived in owner-occupied housing units and 17,042 people (29.9%) lived in rental housing units.