Lake and Peninsula Borough (Russian: Лейк-энд-Пенинсула) 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/km² (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.