The SR 331 designation northward from the St. Joseph Valley Parkway (US 20) is prescribed by state law,[2] as are the locations of the intersections within this section.

[5][6] Between 1980 and 1987 SR 331 was routed east of downtown Mishawaka.

[citation needed] In June 1999 it was relocated eastward north of the St. Joseph Valley Parkway (US 20) in anticipation of a highway upgrade there which had been completed in part.

[7] Although by law the entire project was to have been completed by January 1, 2009,[3] in reality it was finished by September 30, 2013.

[8][9] Subsequently in August 2014 the Indiana Department of Transportation relinquished the parallel portions of the route which it had acquired in 1999.