Summit County is a county in the U.S. state of Utah, occupying a rugged and mountainous area. As of the 2020 United States Census, the population was 42,357. Its county seat is Coalville, and the largest city is Park City.

Coalville is a city in and the county seat of Summit County, Utah, United States. It is part of the Salt Lake City, Utah Metropolitan Statistical Area. The population was 1,486 as of the 2020 census. Interstate 80 passes through the town, as well as the Weber River, which flows into Echo Reservoir, just north of Coalville.