Colloquially known by some as the 21st South Freeway,[2] the route serves as an alternative to Interstate 80 (I-80) through Salt Lake City.

The history of the route predates the invention of the automobile; the Donner Party, California Trail and Pony Express all followed the present-day path of the highway.

Heading generally east with two lanes in each direction, the expressway passes by the Kennecott Smokestack, the tallest structure in Utah.

[3][4] Past its intersection at SR-202, the route takes a turn to the southeast, bypassing the Kennecott tailings pond.

However, an eastbound traveler wanting to continue on the surface portion of SR-201 to State Street must exit on 900 West, head north briefly and then turn eastbound on 2100 South; a westbound traveler on 2100 South wishing to connect to the freeway must take an on-ramp from the surface street just before 900 West.

While signed as the route of the California Trail, modern 2100 South is a less common branch called Hastings Cutoff that became infamous because of the Donner Party.

[29][30] By 1958, SR-201 between US-40 west of Magna and SR-68 (Redwood Road) was a two-lane highway through rural Salt Lake County.

The rural landscape changed by the time SR-201 intersected 300 West and entered urban Salt Lake County, the highway becoming a four-lane road.

From under-construction I-15 west to Redwood Road, the old route of SR-201 was being superseded by a six-lane freeway directly to the south.

[37][38] Beginning in April 1997 and concluding in July 2001, as part of a larger reconstruction project for I-15, SR-201 was rebuilt from 900 West to I-15/I-80, including the colloquial "Spaghetti Bowl" interchange.