The borough has a total area of 32,922 square miles (85,270 km2), of which 23,652 square miles (61,260 km2) is land and 9,270 square miles (24,000 km2) (28.2%) is water. Its land area is larger than that of San Bernardino County, California, the largest county in the contiguous Lower 48 states, and almost as large as the state of West Virginia.
Some 44.70% of households had children under the age of 18 living with them, 48.50% were married couples living together, 9.70% had a female householder with no husband present, and 28.90% were non-families. About 24.70% of all households were made up of individuals, and 3.90% consisted of a sole occupant 65 years of age or older. The average household size was 3.10 and the average family size was 3.74.
In the borough, the age of the population was spread out with 37.80% under the age of 18, 8.50% from 18 to 24, 28.00% from 25 to 44, 20.20% from 45 to 64, and 5.40% who were 65 years of age or older. The median age was 29 years. For every 100 females there were 113.50 males. For every 100 females age 18 and over, there were 124.10 males.