(Covers information from Anderson's universe)
Salt Lake City is the capitol and most populous city in the state of Utah.
In Resident Evil Extinction
5 years after the Global T-Virus pandemic desimated the entire planet, Alice arrives in Salt Lake City on her run from the Umbrella Corporation, she finds the city has been buried deep within a large sand field and is now part of the desert, as the past five years nobody has been around to help keep the sand back.
Salt Lake's sister city, Las Vegas, was also decimated by the sand storms of the Mojave desert over the years, this could mean many other western cities and states were taken by the sandstorms and making the area unpopulatable for the undead due to its conditions.