Umatilla is a city in Umatilla County, Oregon, United States. It is named for the Umatilla River, which enters the Columbia River on the side of the city. The river is named after the Umatilla Tribe. The city is on the south side of the Columbia River along U.S. Route 730 and I-82.The Umatilla Chemical Depot, and the Umatilla Chemical Agent Disposal Facility, is 6 miles southwest of the city, northwest of the intersection of I-84 and I-82. The estimated population in 2017 was 7,245, but the city's population includes approximately 2,000 inmates incarcerated at Two Rivers Correctional Institution. Umatilla's Mayor, Daren Dufloth, was appointed in May, 2017, and owns a strip club in the community.Umatilla is part of the Hermiston-Pendleton Micropolitan Statistical Area.