Your mom is probably right, Lake Tahoe. The Mississippi River is not the kind of river to swim in anywhere.
In the news, they're talking about sometime in 2008 for the new bridge. I suppose all the road salt that had been used for years just deteriorated this bridge, but sheesh! Have it all literally crash in one fall? I used to drive on that bridge, the only one in the state of Minnesota that I actually hated to cross.