http://maps.google.com/maps/ms?hl=en&ie ... e9efb&z=11 All the actual tracks are new construction, but a great deal of the grade (and the bridges) was Milwaukee Road.
If you're able to access the linked map, the orange line is the Milwaukee Road grade and the blue is the LRT. The Milwaukee Road would have crossed Washington Avenue at a viaduct that's no longer there and gone through their downtown Minneapolis freight yard to the Milwaukee Road Depot (now in use as a skating rink and part of a hotel.) Meanwhile, the LRT leaves the Milwaukee grade at the Metrodome, curves around the dome to the west and follows 5th Street to the new Northstar station and Target Field.
Further south around 28th St., the LRT abandons the Milwaukee Road grade and takes a viaduct over MN 55/Hiawatha Avenue, landing on the other side of the highway. The Milwaukee is still in existence south of 28th St. until about 50th St., serving the grain elevators via the Short Line Bridge over the Mississippi to the Minnesota Commercial yards. After 50th St., the Milwaukee grade is obliterated by various roads and trails to 54th St., at which time it starts moving down the bluff as a bike trail, goes around the the bluff at the foot of Historic Fort Snelling, crosses the Minnesota River under the Mendota bridge, and joins the ex-Omaha Road UP line. Meanwhile, south from 50th St. the LRT line follows Minnehaha Avenue for a bit, then winds through the upper post at Fort Snelling (now VA Hospitals and Nat'l Guard facilites), tunnels under the main terminal at the MSP Airport, and hits the Humphrey terminal before winding its way south to the Mall of America.