The Henry Mountains is a mountain range located in the southeastern portion of the U.S. state of Utah that runs in a generally north-south direction, extending over a distance of about 30 miles (48 km). They were named by Almon Thompson in honor of Joseph Henry, the first secretary of the Smithsonian Institution. The nearest town of any size is Hanksville, Utah, which is north of the mountains. The Henry Mountains were the last mountain range to be added to the map of the 48 contiguous U.S. states (1872), and before their official naming by Thompson were sometimes referred to as the "Unknown Mountains." In Navajo, the range is still referred to as Dził Bizhiʼ Ádiní.

Utah is a landlocked state in the Mountain West subregion of the Western United States. It borders Colorado to its east, Wyoming to its northeast, Idaho to its north, Arizona to its south, and Nevada to its west. Utah also touches a corner of New Mexico in the southeast. Of the fifty U.S. states, Utah is the 13th-largest by area; with a population over three million, it is the 30th-most-populous and 11th-least-densely populated. Urban development is mostly concentrated in two areas: the Wasatch Front in the north-central part of the state, which is home to roughly two-thirds of the population and includes the capital city, Salt Lake City; and Washington County in the southwest, with more than 180,000 residents. Most of the western half of Utah lies in the Great Basin.