Note that there is construction affecting the drive to Treasure Island. MN 316 is closed.  It is completely torn up and impassible.  Personally for those of you coming from the North and West the alternate (in dark blue below) of Dakota County 54 to 18 off of 10th Street in Hastings is a much prettier and much more relaxing drive than the very heavily traveled US 61.  So, From the Treasure Island website:

Road Construction on MN 316
Beginning mid April 2004, MN 316 will close to through traffic for needed improvements (shown in red above). We ask that you follow the detour described below in your travels to and from Treasure Island Resort & Casino. As always, we urge you to drive safely.

If you're traveling southbound on Highway 61: Continue south Hwy 61 and follow the signs to Treasure Island Resort & Casino. This is the official MNDOT detour (shown in yellow above).

If you're traveling southbound on Highway 52/55: Continue south on Hwy 52 to Trunk Highway 50. Take a left onto TH 50. TH 50 turns into Hwy 61 South. Continue on Hwy. 61 South and follow signs to Treasure Island Resort & Casino.