Interstate 80 in Utah in the context of "Wasatch Range"

Salt Lake City, often shortened to Salt Lake or SLC, is the capital and most populous city of the U.S. state of Utah. It is the county seat of Salt Lake County, the most populous county in the state. The population was 199,723 at the 2020 census, while the Salt Lake City metropolitan area has an estimated 1.3 million residents and is the 46th-largest metropolitan area in the United States. It is also part of the larger Salt Lake City–Ogden–Provo combined statistical area, an urban corridor along a 120-mile (190 km) segment of the Wasatch Front with a population of approximately 2.8 million. It is one of the principal urban centers within the Great Basin, along with Reno, Nevada.

Salt Lake City was founded in 1847 by settlers led by Brigham Young who were seeking to escape persecution they had experienced while living farther east. The Mormon pioneers, as they would come to be known, entered a semi-arid valley and immediately began building an extensive irrigation network that could feed the population and foster future growth. Salt Lake City's street grid system is based on a standard compass grid plan, with the southeast corner of Temple Square serving as the origin of the Salt Lake meridian. Owing to its proximity to the Great Salt Lake, the city was originally named Great Salt Lake City; the word "Great" was dropped from the city's name in 1868. Immigration of international members of the Church of Jesus Christ of Latter-day Saints (LDS Church), mining booms, and the construction of the first transcontinental railroad brought economic growth, and the city was nicknamed "The Crossroads of the West". It was traversed by the Lincoln Highway, the first transcontinental highway, in 1913. Two major cross-country freeways, I-15 and I-80, now intersect in the city. The city also has a belt route, I-215.

Interstate 215 (I-215), also known locally as the Belt Route, is the only auxiliary Interstate in the U.S. state of Utah, forming a three-quarters loop around Salt Lake City and many of its suburbs. The route begins at the mouth of Parley's Canyon at a junction with I-80 east of the city center, and heads south through the edge of the Salt Lake City metropolitan area's eastern suburbs of Millcreek, Holladay, and Cottonwood Heights. It continues west through Murray before turning north again, passing through the city's first-ring western suburbs of Taylorsville and West Valley City. It then enters North Salt Lake and Davis County for a short distance before reaching I-15 northwest of the city center.

The Interstate was proposed in the mid-1950s, along with I-15 and I-80 through Salt Lake City. At the time, only the western portion of the belt route was assigned as I-215. The eastern portion of the belt route was designated Interstate 415. However, the I-415 designation was scrapped to provide a single route number for the entire route in 1969, with the I-215 designation covering the complete belt route. The freeway was constructed in segments, the first of which opened in 1963 between Redwood Road in North Salt Lake and 2100 North near the airport. I-215 was originally planned to be complete in the mid-1970s, but the last section, between 6200 South and 4500 South in Holladay, was not completed until 1989 because of challenges from citizens' groups over environmental impact statements.