Yeah I live about 90 minutes from Sand Mountain, UT. I think its about (5,000 to 5,200FT)
Just to give you an estimate on what jets to run, look at my mods in my profile....I run 310 mains, stock pilots, needles second notch from blunt end, air screws 1 1/2 out. I would say if your running 310's you could possibly be too rich, even with my 310's in the middle of the summer at 5,000FT I'm a tad rich and I'm running CPI's and Aggressive Dune Porting...etc.
Remember though, the colder it is outside the more fuel you need. I don't ride in this weather, so I keep my 310's in for the summer riding I do.
-Zach