Lake and Peninsula Borough (, Leyk-end-Peninsula) is a borough in the state of Alaska. As of the 2020 census, the population was 1,476, down from 1,631 in 2010. 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 census-designated place of Port Alsworth. With an average of 0.017 /km2, the Lake and Peninsula Borough is the least densely populated organized county-equivalent in the United States; only the unorganized Yukon-Koyukuk Census Area has a lower density.

Geography

The borough has an area of 32922 sqmi, of which 23652 sqmi is land and 9270 sqmi (28.2%) is water. The borough contains Iliamna Lake, the largest lake in Alaska and third largest within United States borders, and 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.

Adjacent boroughs and census areas

National protected areas

Demographics

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 /mi2. There were 1,557 housing units at an average density of 0.05 /mi2. 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. The dominant religion is Orthodox Christianity.

Government

The Borough is governed by an elected assembly. The Borough's mayor is Glen R. Alsworth, Sr. The deputy mayor is Myra J. Olsen. The other members of the assembly are Randy Alvarez, Scott Anderson, Alvin Pedersen, Michelle Pope-Ravenmoon, and Christina Salmon-Bringhurst.

Communities

Despite King Salmon being the borough seat, it is not in Lake and Peninsula Borough and instead in Bristol Bay Borough, therefore it is not included in the list.

Cities

Census-designated places

Ghost town