 The Canada – United States border — with an official crossing into Osoyoos , British Columbia from Oroville — lies approximately 45 miles ( 72 km ) to the north . The Idaho border lies about 160 miles ( 260 km ) southeast . The state 's largest city , Seattle , lies 237 miles ( 381 km ) southwest of Omak . The Okanogan River , coming out of the town of Riverside , defines the city 's northern border , while the southern border is defined by the city of Okanogan ; the terrain here is mountainous and forested . The nearest primary statistical area is the Wenatchee – East Wenatchee metropolitan area . A CDP located northeast of the city was named North Omak because of its proximity to Omak . It is part of two census county divisions : Omak ( western half ) and Colville Reservation ( eastern half ) . 
