John K. Castleberry

JOHN K. CASTLEBERRY is the President and Chief Executive Officer
of WBI Holdings, Inc., the pipeline, energy services, natural gas
and oil production subsidiaries of MDU Resources Group, Inc.
Raised in Wyoming, Mr. Castleberry received a Bachelor’s degree
in Political Economy and a Master’s degree in Economics from the
University of Wyoming. Upon receiving his degree, Castleberry
joined Montana-Dakota Utilities Co., the electric and natural gas
division of MDU Resources as a Regulatory Research Analyst. He
held a number of positions in the Regulatory Affairs Department
of the utility before being named Manager of Revenue and
Certificate Requirements at Williston Basin Interstate Pipeline
Co. where he was charged with creating a Regulatory Affairs
Department in the newly formed company subsidiary. In 1995, Mr.
Castleberry was named President of WBI Holdings, Inc. and was
also named their Chief Executive Officer in 1998. He is active in
natural gas industry associations and in the Bismarck community
where he serves on the board for the Bismarck State College
Foundation.