Interstate Companies | Home Page Interstate Companies | Home Page Home Page Mission Statement Announcements Contact Us Other Interstate Companies AssemblySystems BearingSystems PowerSystems PowerSystems Transport Refrigeration Power Systems Interstate Companies, Inc. is the parent company of a diversified group of businesses servicing a wide territory that includes Minnesota, Wisconsin, Nebraska, Iowa, Illinois, North Dakota, South Dakota, Montana, and Wyoming. From the Great Lakes to the Rocky Mountains, Interstate has a location near you. Interstate PowerSystems is a distributor for Detroit