 The 1910 United States Census, before the city's incorporation, recorded 520 residents.The following 1920 censusthe first to define Omak as a distinct subdivisioncounted 2,500 residents, making it the most populous municipality of Okanogan County, having surpassed Okanogan (1,519 residents).Subsequent census counts documented an increase to 4,000 residents before a shrink in population at the 1980 census, when fruit prices rose, land was lost, and major employers were shut down.