families (71.1% of all households); the average family size was 2.89. The population was spread out, with 127 people (20.8%) under the age of 18, 37 people (6.1%) aged 18 to 24, 122 people (20.0%) aged 25 to 44, 237 people (38.9%) aged 45 to 64, and 87 people (14.3%) who were 65 years of age or older. The median age was 46.9 years. For every 100 females, there were 112.5 males. For every 100 females age 18 and over, there were 105.5 males. There were 314 housing units at an average density of , of which 193 (79.8%) were owner-occupied, and 49 (20.2%) were occupied by renters. The homeowner vacancy rate was 1.5%; the rental vacancy rate was 7.5%. 469 people (76.9% of the population) lived in owner-occupied housing units and 125 people (20.5%) lived in rental housing units. References External links Sierra Nevada Virtual Museum: Alta Unincorporated communities in California Census-designated places in Placer County, California Census-designated places in California