From The Vault
||The following is based on Van Buren and has not been confirmed by canon sources.
Most of Salt Lake City and Ogden, Utah were destroyed in the Great War in 2077. When Vault 70 opened in 2190 the residents used their three G.E.C.K.s to found the city of New Jerusalem in the ruins of Salt Lake City. It is unknown why Vault 70 received more G.E.C.K.s than any other Vault, it is logical to assume that the already unfriendly environment of Utah prompted extra jump-starting after a nuclear apocalypse.
New Jerusalem's intolerant prophet and apostles repeatedly voted to have no commerce with outsiders from other, failed communities, refugees, or tribals. In 2233, a number of angry tribals, raiders, and disassociated attackers ganged up on New Jerusalem and sacked it, killing most of the Mormons in the process.
The new living prophet, Judah Black, led most of the remnants of the Mormon community north to Ogden, Utah. They established the town of New Canaan.
According to Burham Springs design document, Salt Lake City is unsuitable for the NCR outpost, as is Burham Springs, affected by constant fire.
Salt Lake City Mining Consortium is mentioned as being located in Salt Lake City in an example location checklist given by Chris Avellone in the Tibbets Prison design document.