Can anyone tell me from the MPLS area where the 4th of July fireworks are usually located at, I'm spending this 4th of July in the cities.

There are a whole BUNCH of displays in the twin cities area.
Taste of Minnesota in St Paul is probably the best fireworks in the area specifically on the 4th of July, but there is a display in downtown Mpls also. Watch from the Hennepin avenue bridge, or walk down by the river for the best views.
The best fireworks in the state happen for the Minneapolis aquatennial. Called the 'big ooh ahh!', it's one of the top 5 fireworks displays in the entire country, but that usually happens later in July.

Taste of Minnesota - Harriet Island in St. Paul. The best display in the cities and an amazing sampling of Twin Cities restaurants.

yeah. what they said.