Interlaken is a census-designated place (CDP) in Santa Cruz County, California, United States. The population was 7,368 at the 2020 census. Like its namesake, it is situated amongst College Lake, Pinto Lake, Kelly Lake, Lake Tynan, and Drew Lake.
Geography
Interlaken is located at (36.956293, -121.745433).
According to the United States Census Bureau, the CDP has a total area of , of which (96.13%) is land and (3.87%) is water.
Demographics
Interlaken first appeared as a census designated place in the 1990 U.S. census.
!Pop 2010
!style="background-color: #ffffb3;" |Pop 2020
!% 2000
!% 2010
!style="background-color: #ffffb3;" |% 2020
|-
|White alone (NH)
|2,179
|1,613
|style='background: #ffffe6; |1,378
|29.74%
|22.03%
|style='background: #ffffe6; |18.70%
|-
|Black or African American alone (NH)
|49
|32
|style='background: #ffffe6; |30
|0.67%
|0.44%
|style='background: #ffffe6; |0.41%
|-
|Native American or Alaska Native alone (NH)
|39
|22
|style='background: #ffffe6; |17
|0.53%
|0.30%
|style='background: #ffffe6; |0.23%
|-
|Asian alone (NH)
|364
|256
|style='background: #ffffe6; |197
|4.97%
|3.50%
|style='background: #ffffe6; |2.67%
|-
|Native Hawaiian or Pacific Islander alone (NH)
|5
|1
|style='background: #ffffe6; |4
|0.07%
|0.01%
|style='background: #ffffe6; |0.05%
|-
|Other race alone (NH)
|4
|8
|style='background: #ffffe6; |38
|0.05%
|0.11%
|style='background: #ffffe6; |0.52%
|-
|Mixed race or Multiracial (NH)
|137
|128
|style='background: #ffffe6; |161
|1.87%
|1.75%
|style='background: #ffffe6; |2.19%
|-
|Hispanic or Latino (any race)
|4,551
|5,261
|style='background: #ffffe6; |5,543
|62.10%
|71.86%
|style='background: #ffffe6; |75.23%
|-
|Total
|7,328
|7,321
|style='background: #ffffe6; |7,368
|100.00%
|100.00%
|style='background: #ffffe6; |100.00%
|}
2020 census
As of the 2020 census, Interlaken had a population of 7,368. The population density was .
The age distribution was 25.7% under the age of 18, 9.9% aged 18 to 24, 27.0% aged 25 to 44, 23.6% aged 45 to 64, and 13.8% who were 65 years of age or older. The median age was 35.1 years. For every 100 females there were 101.3 males, and for every 100 females age 18 and over there were 100.7 males age 18 and over.
There were 1,841 households, of which 48.3% had children under the age of 18 living in them. Of all households, 58.9% were married-couple households, 7.1% were cohabiting-couple households, 13.0% were households with a male householder and no spouse or partner present, and 21.0% were households with a female householder and no spouse or partner present. About 11.4% of all households were made up of individuals and 6.0% had someone living alone who was 65 years of age or older. The average household size was 3.97. There were 1,527 families (82.9% of all households).
The census reported that 98.5% of the population lived in households and 1.5% lived in non-institutionalized group quarters.
There were 1,690 households, 885 (52.4%) had children under the age of 18 living in them, 1,075 (63.6%) were opposite-sex married couples living together, 227 (13.4%) had a female householder with no husband present, 123 (7.3%) had a male householder with no wife present. There were 92 (5.4%) unmarried opposite-sex partnerships, and 11 (0.7%) same-sex married couples or partnerships. 179 households (10.6%) were one person and 88 (5.2%) had someone living alone who was 65 or older. The average household size was 4.27. There were 1,425 families (84.3% of households); the average family size was 4.43.
The age distribution was 2,138 people (29.2%) under the age of 18, 853 people (11.7%) aged 18 to 24, 2,039 people (27.9%) aged 25 to 44, 1,658 people (22.6%) aged 45 to 64, and 633 people (8.6%) who were 65 or older. The median age was 30.5 years. For every 100 females, there were 109.6 males. For every 100 females age 18 and over, there were 106.7 males.
There were 1,759 housing units at an average density of , of which 71.4% were owner-occupied and 28.6% were occupied by renters. The homeowner vacancy rate was 0.7%; the rental vacancy rate was 1.8%. 68.6% of the population lived in owner-occupied housing units and 29.8% lived in rental housing units.
Demographic estimates
In 2023, the US Census Bureau estimated that 31.2% of the population were foreign-born. Of all people aged 5 or older, 36.3% spoke only English at home, 62.1% spoke Spanish, 1.6% spoke other Indo-European languages, 0.0% spoke Asian or Pacific Islander languages, and 0.0% spoke other languages. Of those aged 25 or older, 73.3% were high school graduates and 18.0% had a bachelor's degree.
Income and poverty
The median household income in 2023 was $111,021, and the per capita income was $36,003. About 3.9% of families and 8.2% of the population were below the poverty line.
Government
In the California State Legislature, Interlaken is in , and in .
In the United States House of Representatives, Interlaken is in .