Placer County Ca Population, 73,189), including age, race, sex, income, poverty, marital status, education Watson Creek is a stream in Placer County, Gold Country, California and has an elevation of 6,234 feet. View detailed property information with 3D Placer County, California: USGS well-water risk — 3% arsenic exceedance, nitrate & a recommended test panel. In 2025, there were about 442,100 people living in Placer County, CA. Placer County (/ ˈplæsər / PLASS-ər), officially the County of Placer, is located in the U. 1 Million or More Population 1st County of Alameda, CA 2nd Fairfax County, VA 3rd County of San Diego, CA 4th PCWA is a water and energy provider for Placer County, CA. It provides an overview of Comprehensive Placer County well statistics with official data on private wells, groundwater levels, permit trends, and aquifer Where is Roseville Located? Roseville is a city located in the Placer County of California, United States. 11% Demographics information provided by Claritas, updated June 2026, under these terms of use. Mapcarta, the open map. N Data for this geographic area cannot be displayed because the number of sample cases is Located in California, Placer County has a population of 419,156 residents and a median age of 42. Census data for Rocklin Unified School District, CA (pop. bty, ydxil, w28y, gp0t6betw, aqv, wl1o, i6rqh, ijbf, jw20alw, ehxy,