What do you like to do? You'll be in my stomping grounds.
There is, of course, all the Mormon things: Temple Square and the like. Worth a visit, but maybe just a morning.
Kennecot copper mine is the world's largest open pit mine. Impressive, big ugly scar.
The lake isn't really much to look at and the weather is wrong for experiencing the high buoyancy of the salt water. On the other hand, no brine flies.
Park City is 1/2 hour away. That's where most of the best restaurants concentrate. The mountains should be wearing their winter coat of snow, but not quite enough to ski on. The Deer Valley resort is there too and the Glitterrien is renowned eating and has a top 50 in the nation wine list as I recall.
I don't eat much in Park City as I'm not up there much. If you can get to the Log Haven up Mill Creek Canyon, they have great eats. It's even closer than Park City and better location, IMHO. La Caille is popular with the French style crowd, though their reputation is slipping. Christophers is good seafood and steak at least for this far from the coast.
Robert Redford's Sundance resort is about an hour away. He's got good eatin' and a good location too. The Tree Room is the signature room at the restaurant with the trunk of a large live tree rising up through it.
Of local entrepeneurship, Gastronomy Inc, runs some good places. Baci Trattoria, New Yorker, Pierpont, Market Street Grill. Not Gastronomy, but the Metropolitan is credited highly for their game dishes. Al Fresco is good italian.
The Urban is my favorite lunch, but usually closed for dinner with other gigs. His other endeavor is a late night place Orbitz or some such. Haven't been yet.
Zagat recommends all those highly too.
If you're willing to go a bit odd and lower end, Cafe Trang is good Vietnamese. Their one mall location has gone more mainstream. Go to the one downtown. There are a number of South American joints. El Chalan (or Chalau, the sign is hard to read) has a good rep for Peruvian. Il Itzalquena does good Salvadoran. For lunch downtown, Sigfried's Delicatessen is good German food. Happy Sumo is good sushi. My favorite Indian food is the Royal India. There are lots of good Mexican dives but you want to go to the poorer sections of town for the best ones.
Let me know, perhaps we can meet up.