Northern States Power Company

Northern States Power Company was a publicly traded S&P 500 electric and natural gas utility holding company based in Minneapolis, Minnesota that is now a subsidiary of Xcel Energy.
 
While the bulk of NSP's territory grew across central and southern Minnesota (starting from the Twin Cities), it acquired territory in North Dakota (centering on Fargo, Grand Forks, and Minot) and grew southwest into South Dakota (centering on Sioux Falls). Its territory extended east into Wisconsin as well, but due to state regulations requiring local ownership of all utilities, these operations were under a separate subsidiary: Northern States Power-Wisconsin. This latter subsidiary extended east into northern neighboring Upper{eninsula of Michigan, bounded between Lake Michigan and Lake Superior around 1995.