Mesa County, Colorado

Mesa County is a county in the U.S. state of Colorado. As of the 2020 census, the population was 155,703, making Mesa County the most populous county in western Colorado, and the 11th-most populous in the state. The county seat and most populous municipality is Grand Junction. The county was named for the many large mesas in the area, including the Grand Mesa, the largest flat-topped mountain in the world.