EXHIBIT 21-SUBSIDIARIES OF THE REGISTRANT State of Jurisdiction of Incorporation Name or Limited Partnership - ----------------------------- ------------------------------------- NorthWestern Corporation Delaware Grant, Inc. South Dakota NorCom Advanced Technologies, Inc. South Dakota NorthWestern Energy Corporation South Dakota Nekota Resources Inc. South Dakota NorthWestern Growth Corporation South Dakota Blue Dot Services, Inc. Delaware Coast Energy Capital Corporation Delaware CornerStone Propane GP, Inc. California CornerStone Propane Partners, L.P. Delaware Limited Partnership CornerStone Propane, L.P. Delaware Limited Partnership Expanets, Inc. Delaware NorthWestern Capital Corporation Delaware NorthWestern Networks, Inc. South Dakota NorthWestern Systems, Inc. South Dakota Lucht Inc. Delaware SYN Inc. Delaware NorthWestern Services Corporation South Dakota