Omak is a city located in the foothills of the Okanogan Highlands in north-central Washington, United States. With an estimated 4,854 residents as of 2015, distributed over a land area of 3.43 square miles, Omak is the largest municipality of Okanogan County and the largest municipality in Central Washington north of Wenatchee. The Greater Omak Area of around 8,229 inhabitants as of the 2010 census is the largest urban cluster in the Okanogan Country region, encompassing most of its twin city of Okanogan. The population has increased significantly since the 1910 census, reporting 520 residents just prior to incorporation in 1911.The land that is now Omak had been inhabited by various Native American tribes before the arrival of non-indigenous settlers in the early 19th century. The city began to develop after the completion of the Okanogan Irrigation Project affecting the Grand Coulee Dam and other nearby electric facilities.