Minnesota State Highway business route marker
<a href="https://en.wikipedia.org/wiki/Minnesota_Department_of_Transportation" class="extiw" title="w:Minnesota Department of Transportation">Minnesota Department of Transportation</a>
<a rel="nofollow" class="external text" href="http://www.dot.state.mn.us/trafficeng/publ/signsmanual/standardsigns-2013-mseries.pdf">Minnesota Standard Signs Manual</a>