25

MDU RESOURCES G ROUP, INC.

Corporate Management

Steven L. Bietz, 49 (27)

Mark Del Vecchio, 48 (4)

Bruce T. Imsdahl, 59 (37)

John G. Harp, 55 (32)

Terry D. Hildestad, 58 (33)

President and

President and

Vice President of Human

President and

President and

Chief Executive Officer,

Chief Executive Officer,

Resources, MDU Resources

Chief Executive Officer,

Chief Executive Officer,

MDU Resources

WBI Holdings, Inc.

MDU Construction Services

Montana-Dakota Utilities Co.

Formerly director of

Group, Inc.

and Great Plains Natural Gas

Serves on the company's

Formerly held executive and

compensation and executive

Co.; Chief Executive Officer,

Board of Directors and as

management positions with

programs of MDU Resources

Formerly owned

Cascade Natural Gas Corp.

chairman of the board of

WBI Holdings

construction services

major subsidiary companies;

companies that were

Formerly held executive and

formerly chief operating

acquired by MDU Resources

management positions with

officer of MDU Resources

Montana-Dakota

and formerly president and

chief executive officer of

Knife River Corporation

Cynthia J. Norland, 53 (23)

William E. Schneider, 58 (14)

Paul K. Sandness, 53 (27)

Vernon A. Raile, 62 (27)

Vice President

Executive Vice President,

General Counsel and

President and

of Administration,

Treasurer and Chief Financial

Secretary, MDU Resources

Chief Executive Officer,

MDU Resources

Officer, MDU Resources

Knife River Corporation

Serves as general counsel

Formerly associate general

Serves as the senior financial

and secretary for all major

Serves as chief executive

counsel of MDU Resources

officer and member of the

company subsidiaries;

officer of all construction

boards of directors of all

formerly senior attorney and

materials and contracting

major subsidiary companies;

held other positions of

subsidiaries of Knife River;

formerly chief accounting

increasing responsibility with

formerly senior vice

officer of MDU Resources

MDU Resources

president of construction

materials of Knife River

Management Changes

Other Corporate and

Bruce T. Imsdahl, president

John K. Castleberry,

Senior Company Officers

and chief executive officer of

executive vice president

Nicole A. Kivisto, 34 (12)

Montana-Dakota Utilities Co.

of administration, retired

Controller, MDU Resources

and Great Plains Natural Gas

July 6, 2007.

Co. and chief executive

Doran N. Schwartz, 38 (3)

Cynthia J. Norland was

officer of Cascade Natural

Vice President and Chief

named vice president of

Gas Corp., announced

Accounting Officer, MDU

administration July 16, 2007.

January 17, 2008, that he will

Resources

retire effective June 5, 2008.

Cindy C. Redding resigned

John P. Stumpf, 48 (15)

as vice president of

David L. Goodin, on

Vice President of Strategic

human resources effective

January 22, 2008, was

Planning, MDU Resources

July 6, 2007.

named president of

Montana-Dakota Utilities Co.

Mark Del Vecchio was named

and Great Plains Natural Gas

vice president of human

Co., effective March 1, 2008.

resources October 1, 2007.

He also continues his

position as president of

Cascade Natural Gas Corp.

Numbers indicate age

and years of service ( ) as

of December 31, 2007.