Mankato has historically been hit by a series of large floods. Federal funding for floodwalls was repeatedly turned down by the government, until it was finally approved in the late 1950s. That project was never started, and in 1965, the food of the century hit. That flood caused a huge amount of damage in downtown Mankato when the make-shift dikes gave away. As a result of the flood, the flood protection project was finally put into high gear. That project built levees on both sides of the river, and capped those levees with floodwalls. The US-14 bridge was lower than the floodwalls, so it had to be removed. It was replaced with the new Veteran's Memorial Bridge. The North Star Bridge was high enough, but the levees and floodwall just barely cleared under the bridge structure. Since that time, the flood protection system has worked very well, protecting the city from several 50 and 100 year floods in the late 1990s and early 2000s.
By the late 1980s, the pavement on the US-169 bypass had reached the end of its life, and the bridge was in need of repairs. As a result, MN-DOT funded a project to rebuild the US-169 bypass, put in new concrete pavement, widen the shoulders, and put in modern guardrails. This allowed MN-DOT to raise the speed limit on the highway from the traditional 50 MPH to the more normal 55 MPH.
The North Star Bridge is the third of three bridges to carry US-169 across the Minnesota River when heading upstream from the Twin Cities. The other two crossings are the Bloomington Ferry Bridge in the southwest metro area, and the US-169 bridge at Le Sueur.
