Garfield County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 61,685, making it the second-most populous county in western Colorado and the 13th-most populous in the state. The county seat is Glenwood Springs, and the largest community is Rifle. The county is named in honor of United States President Jame…Garfield County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 61,685, making it the second-most populous county in western Colorado and the 13th-most populous in the state. The county seat is Glenwood Springs, and the largest community is Rifle. The county is named in honor of United States President James A. Garfield.