About Placer County

Placer County , California

Officially the County of Placer, is a county located in the U.S. state of California. As of the 2024 census, the population was 433,882. The county seat is Auburn. Placer County is included in the Greater Sacramento metropolitan area. It is in both the Sacramento Valley and Sierra Nevada regions, in what is known as the Gold Country. The county stretches roughly 65 miles (105 km) from Sacramento's suburbs at Roseville to the Nevada border and the shore of Lake Tahoe. 

Placer County, California, was established on April 25, 1851, during the California Gold Rush, and its name reflects the mining history of the area. The county was formed from parts of Sutter County and Yuba County, with Auburn serving as the county seat. Placer County derives its name from the Spanish word for "sand or gravel deposits containing gold," reflecting the placer mining practices common in the area.  

Gold mining was a major industry through the 1880s, but gradually the new residents turned to farming the fertile foothill soil, harvesting timber and working for the Southern Pacific Railroad. Auburn was settled when Claude Chana discovered gold in Auburn Ravine in May 1848, and it later became a shipping and supply center for the surrounding gold camps. The cornerstone of Placer's courthouse, which is clearly visible from Interstate 80 through Auburn, was laid on July 4, 1894. The building was renovated during the late 1980s and continues to serve the public with courtrooms, a sheriff's office and the Placer County Museum. Roseville, once a small agricultural center, became a major railroad center and grew to the county's most populous city after Southern Pacific Railroad moved its railroad switching yards there in 1908.

Loomis and Newcastle began as mining towns, but soon became centers of a booming fruit-growing industry, supporting many local packing houses. Penryn was founded by a Welsh miner, Griffith Griffith, who established a large granite quarry. Rocklin began as a railroad town and became home to a number of granite quarries. Lincoln and Sheridan continue to support ranching and farming. Lincoln also is the home of one of the county's oldest businesses, the Gladding, McBean terra cotta clay manufacturing plant, established in 1875.

The county is typically divided into three regions; “South Placer” in the Central Valley and the Sierra Nevada foothills south of Auburn, “Gold Country” which consists of the Sierra Foothills around Auburn, Colfax, and Foresthill, and the Sierra Nevada which consists of all areas east of Foresthill and northeast of Colfax (including the Lake Tahoe region). Roughly 3/4ths of the population lives in South Placer, Roseville being the primary job and retail center of the county. Auburn and Lincoln are the main secondary commercial centers.