Grand Junction is a home rule municipality that is the seat of government and largest city of Mesa County, Colorado, United States. Grand Junction's population was 65,560 at the 2020 United States Census, making it the most populous city in western Colorado and the 17th most populous Colorado municipality overall.

The Western Slope is a colloquial term generally understood to describe the part of the state of Colorado west of the Continental Divide. Bodies of water west of the Divide flow toward the Pacific Ocean; water that falls and flows east of the Divide heads east toward the Gulf of Mexico. The Western Slope encompasses about 33% of the state, but has just 10% of the state's residents. The eastern part of the state, including the San Luis Valley and the Front Range, is the more populous portion of the state.