Tarkio is an unincorporated community in Montana, United States, located in Mineral County. Tarkio falls in Mountain Time Zone (MST/MDT) and observes daylight saving time. Tarkio's elevation is 2936 ft above sea level, and is approximately 40 mi outside of Missoula. It lies along Interstate 90 with access via exit 61. The Clark Fork River flows to the west.