Parker is the county seat of La Paz County, Arizona, United States, on the Colorado River in Parker Valley. As of the 2020 census, the population of the city was 3,417. Founded in 1908, the town was named after Ely Parker, the first Native American commissioner for the U.S. government. The original town site of Parker was surveyed and laid out in 1909 b…Parker is the county seat of La Paz County, Arizona, United States, on the Colorado River in Parker Valley. As of the 2020 census, the population of the city was 3,417. Founded in 1908, the town was named after Ely Parker, the first Native American commissioner for the U.S. government. The original town site of Parker was surveyed and laid out in 1909 by Earl H. Parker, a railroad location engineer for the Arizona & California Railway. The town officially incorporated in 1948 and became the county seat for the newly created La Paz County on January 1, 1983.