Lake and Peninsula Borough is a borough in the state of Alaska. As of the 2010 census, the population was 1,631. The borough seat of King Salmon is located in neighboring Bristol Bay Borough, although is not the seat of that borough. The most populous community in the borough is the city of Newhalen. With an average of 0.0296 inhabitants/km (0.0767/sq mi), the Lake and Peninsula Borough is the second least densely populated organized county-equivalent in the United States; only the unorganized Yukon-Koyukuk Census Area has a lower density.
The borough has an area of 32,922 square miles (85,270 km), of which 23,652 square miles (61,260 km) is land and 9,270 square miles (24,000 km) (28.2%) is water. The borough occupies most of the Alaska Peninsula. 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.
As of the census of 2000, there were 1,823 people, 588 households, and 418 families residing in the borough. The population density was 0.059 people per square mile (0.023/km). There were 1,557 housing units at an average density of 0.05 per square mile (0.02/km). The racial makeup of the borough was 18.76% White, 0.05% Black or African American, 73.51% Native American, 0.22% Asian, 0.16% Pacific Islander, 0.33% from other races, and 6.97% from two or more races. 1.15% of the population were Hispanic or Latino of any race. About 5.41% reported speaking a Yupik language at home, while 3.87% speak Alutiiq and 1.23% an Athabaskan language .
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.
Peninsula Borough Alaska neighborhoods include: Echo Lake Rd / Gaswell Rd, Grove Ave, K-Beach / Soldotna-Poppy, Kenai Spur Hwy, Mackey Lake, Poppy Ridge