St. George is a city in and the county seat of Washington County, Utah, United States. Located in the southwestern part of the state on the Arizona border, near the tri-state junction of Utah, Arizona and Nevada, it is the principal city of the St. George Metropolitan Statistical Area. The city lies in the northeasternmost part of the Mojave Desert, adjacent to the Pine Valley Mountains near the convergence of three distinct geological areas: the Mojave Desert, Colorado Plateau, and Great Basin. The city is 118 mi northeast of Las Vegas and 300 mi south-southwest of Salt Lake City on Interstate 15. The St. George area is well known for its natural environment and proximity to several state and national parks.