Hidden Valley Lake first appeared as a
census designated place in the
1990 U.S. census. 0.0% of residents lived in urban areas, while 100.0% lived in rural areas. The age distribution was 23.2% under the age of 18, 6.3% aged 18 to 24, 22.4% aged 25 to 44, 28.3% aged 45 to 64, and 19.8% who were 65 years of age or older. The median age was 43.2 years. For every 100 females, there were 97.3 males, and for every 100 females age 18 and over there were 97.7 males age 18 and over. There were 2,612 housing units at an average density of , of which 2,354 (90.1%) were occupied. Of the occupied units, 81.6% were owner-occupied and 18.4% were occupied by renters. 9.9% of housing units were vacant. The homeowner vacancy rate was 2.2%, and the rental vacancy rate was 4.6%.
2010 census The
2010 United States census reported that Hidden Valley Lake had a population of 5,579. The population density was . The racial makeup of Hidden Valley Lake was 4,830 (86.6%)
White, 63 (1.1%)
African American, 80 (1.4%)
Native American, 75 (1.3%)
Asian, 12 (0.2%)
Pacific Islander, 326 (5.8%) from
other races, and 193 (3.5%) from two or more races.
Hispanic or
Latino of any race were 733 persons (13.1%). The Census reported that 5,575 people (99.9% of the population) lived in households, 4 (0.1%) lived in non-institutionalized group quarters, and 0 (0%) were institutionalized. There were 2,119 households, out of which 752 (35.5%) had children under the age of 18 living in them, 1,291 (60.9%) were
opposite-sex married couples living together, 206 (9.7%) had a female householder with no husband present, 93 (4.4%) had a male householder with no wife present. There were 155 (7.3%)
unmarried opposite-sex partnerships, and 23 (1.1%)
same-sex married couples or partnerships. 388 households (18.3%) were made up of individuals, and 138 (6.5%) had someone living alone who was 65 years of age or older. The average household size was 2.63. There were 1,590
families (75.0% of all households); the average family size was 2.98. The population was spread out, with 1,400 people (25.1%) under the age of 18, 296 people (5.3%) aged 18 to 24, 1,413 people (25.3%) aged 25 to 44, 1,706 people (30.6%) aged 45 to 64, and 764 people (13.7%) who were 65 years of age or older. The median age was 41.2 years. For every 100 females, there were 97.2 males. For every 100 females age 18 and over, there were 95.8 males. There were 2,597 housing units at an average density of , of which 1,687 (79.6%) were owner-occupied, and 432 (20.4%) were occupied by renters. The homeowner vacancy rate was 6.1%; the rental vacancy rate was 8.2%. 4,274 people (76.6% of the population) lived in owner-occupied housing units and 1,301 people (23.3%) lived in rental housing units. ==Government==