Controversial-radical point of view WARNING. Please don't continue if you don't like engaging in never ending debates.
Very radical and controversial point of view, but the Fire Fly's do have a similar story to the Mormons: hated and rejected by the government and forced to move out west to uphold their utopian radical views.
And why Salt Lake City as their final destination? What do they need with a big lake of salt water anyways? Not the mention that over half the city before the infection are Mormon. So, if they're any survivors after 20 years... guess what the fire flys are going to find: more religious psuedo terrorists; something a little bit similar, minus the terrorist part.
Maybe just like the mormons nobody wanted to live there except them. It was crawling with infected, but there was no hunters: I litteraly walked through the whole city without fireing a sigle round.
Through that whole walk through, of all the giraffs and scenery you see, there's no sign of that famous Mormon temple that the city is so recognized for. Maybe ND really wanted to do all they could to avoid this correlation, eventhough there's an obvious parrael.
Wait a minute, it was there?? Man, I really wasn't looking for it, But that leads us even deeper into this discussion. They showed us downtown Austin, but did not include the famous Frost Bank building (litterally the 8 wonder of Texas). So when they put something in, its for a reason. They could have easily have left that out.
I don't see the parallel at all, you should construct your argument a bit better than just locations and being "hated by the government" - They are hated by the current Military because they want the three branches of government back, they think that the Military has held onto their power for long enough and have rebelled against them to liberate themselves from them. Any quarantine zones still alive know what has happened with rebellions and the effect a small uprising can have, therefore, they kill any sign of rebellion on sight.
As for Salt Lake City, they were originally based in Colorado, but moved. Who knows why, but it could have been for many reasons. Probably because they found a large hospital that was still in excellent condition to be used as a new HQ, with enough infected near to use as protection, but no nearby human civilisations to be seen as a threat. Whatever the reason, I don't see the link to Mormonism.