where is adams county washington state
Adams County, Washington. Adams County is a county in the U.S. state of Washington. As of the 2010 census, the population was 18,728.[1] The county seat is at Ritzville, and its largest city is Othello. The county was formed out of Whitman County on November 28, 1883[2] and is named for the second President of the United States, John Adams.