Ferry County is a county located in the U.S. state of Washington. As of the 2010 census, the population was 7,551, making it the fourth-least populous county in Washington. The county seat and largest city is Republic. The county was created out of Stevens County on February 21, 1899 and is named for Elisha P. Ferry, the state's first governor.
The least populated county has 1052 people. 
There is no data on the population of the other counties, but nothing contradicts it.