Exhibit 21-A

OTTER TAIL CORPORATION

Subsidiaries of the Registrant

February 29, 2016

Company	State of Organization
Otter Tail Power Company		Minnesota
Otter Tail Energy Services Company, Inc.		Minnesota
Sheridan Ridge II, LLC		Minnesota
Otter Tail Assurance Limited		Cayman Islands
Varistar Corporation		Minnesota
Northern Pipe Products, Inc.		North Dakota
Vinyltech Corporation		Arizona
T.O. Plastics, Inc.		Minnesota
IMD, Inc.		North Dakota
BTD Manufacturing, Inc.		Minnesota
Miller Welding & Iron Works, Inc.		Minnesota
Shrco, Inc.		Minnesota
ASI, Inc.		Minnesota
AEV, Inc.		Minnesota