Utah Paintball Xtreme. 7050 South 400 West in Midvale. Take I-15 to the 7200 South exit, go East about a block then north.
www.uxpaintball.com/
Nice guys up there, but call ahead to make sure their tanks are up to pressure. Went in last night, and since Friday is very busy, they'd drawn the air pressure down to around 3500 PSI, so filled my bottle to that point for free. Need to go back today and refill, after shooting this morning.
By the way, the new TNT Gun Range has a great 25 yard indoor pistol range that they allow rifles on. Shot there for an hour an a half this morning with only two other shooters. Lanes are wide and enough bench to shoot on a bi-pod with a Marauder. Really friendly folks at both places.
What part of Salt Lake are you in?