Lake Telemark is an unincorporated community and census-designated place (CDP) in Rockaway Township, Morris County, New Jersey, United States. As of the 2020 census, the CDP's population was 1,172. 1960 1970<br> 1980 1990 2000<br> 2010 2020
!Pop 2010
!style="background-color: #ffffb3;" |Pop 2020
!% 2000
!% 2010
!style="background-color: #ffffb3;" |% 2020
|-
|White alone (NH)
|1,139
|1,145
|style='background: #ffffe6; |1,000
|94.76%
|91.24%
|style='background: #ffffe6; |85.32%
|-
|Black or African American alone (NH)
|4
|20
|style='background: #ffffe6; |17
|0.33%
|1.59%
|style='background: #ffffe6; |1.45%
|-
|Native American or Alaska Native alone (NH)
|1
|1
|style='background: #ffffe6; |4
|0.08%
|0.08%
|style='background: #ffffe6; |0.34%
|-
|Asian alone (NH)
|15
|22
|style='background: #ffffe6; |52
|1.25%
|1.75%
|style='background: #ffffe6; |4.44%
|-
|Native Hawaiian or Pacific Islander alone (NH)
|1
|0
|style='background: #ffffe6; |0
|0.08%
|0.00%
|style='background: #ffffe6; |0.00%
|-
|Other race alone (NH)
|1
|1
|style='background: #ffffe6; |0
|0.08%
|0.08%
|style='background: #ffffe6; |0.00%
|-
|Mixed race or Multiracial (NH)
|6
|13
|style='background: #ffffe6; |11
|0.50%
|1.04%
|style='background: #ffffe6; |0.94%
|-
|Hispanic or Latino (any race)
|35
|53
|style='background: #ffffe6; |88
|2.91%
|4.22%
|style='background: #ffffe6; |7.51%
|-
|Total
|1,202
|1,255
|style='background: #ffffe6; |1,172
|100.00%
|100.00%
|style='background: #ffffe6; |100.00%
|}
2010 census
The 2010 United States census counted 1,255 people, 439 households, and 359 families in the CDP. The population density was . There were 464 housing units at an average density of . The racial makeup was 93.78% (1,177) White, 1.67% (21) Black or African American, 0.08% (1) Native American, 1.75% (22) Asian, 0.00% (0) Pacific Islander, 1.12% (14) from other races, and 1.59% (20) from two or more races. Hispanic or Latino of any race were 4.22% (53) of the population.
Of the 439 households, 38.3% had children under the age of 18; 66.3% were married couples living together; 11.2% had a female householder with no husband present and 18.2% were non-families. Of all households, 14.4% were made up of individuals and 5.5% had someone living alone who was 65 years of age or older. The average household size was 2.86 and the average family size was 3.16.
There were 414 households, out of which 44.2% had children under the age of 18 living with them, 71.7% were married couples living together, 8.9% had a female householder with no husband present, and 16.9% were non-families. 15.2% of all households were made up of individuals, and 4.8% had someone living alone who was 65 years of age or older. The average household size was 2.90 and the average family size was 3.24.