2020 census As of the
2020 census, Captain Cook had a population of 3,253. The median age was 45.6 years. 20.0% of residents were under the age of 18 and 27.1% of residents were 65 years of age or older. For every 100 females there were 88.0 males, and for every 100 females age 18 and over there were 85.7 males age 18 and over. 0.0% of residents lived in urban areas, while 100.0% lived in rural areas. There were 1,116 households in Captain Cook, of which 28.6% had children under the age of 18 living in them. Of all households, 51.4% were married-couple households, 18.1% were households with a male householder and no spouse or partner present, and 22.8% were households with a female householder and no spouse or partner present. About 22.7% of all households were made up of individuals and 14.7% had someone living alone who was 65 years of age or older. There were 1,258 households, out of which 22.0% had children under the age of 18 living with them. The average household size was 2.73. ==Lava zones, redlining, and insurance issues==