Joseph Ganahl, 67, a retired Army officer and systems engineer who also worked for defense system contracting firms, died of respiratory failure Jan. 11 at his home in Great Falls. He had a neurological disorder.

Col. Ganahl was a project manager in the Washington area for IBM, Loral and Lockheed Martin corporations after he retired from the Army in 1977. He retired again last March.

He was born in Fort Sill, Okla. He was a graduate of the U.S. Military Academy at West Point and received a master's degree in mathematics from Rensselaer Polytechnic Institute.

He taught math at West Point in the early 1960s and commanded an artillery battalion in Vietnam in the early 1970s. He retired from a computer systems engineering assignment.

Col. Ganahl's honors included two Legions of Merit, a Bronze Star, a Meritorious Service Medal and an Army Commendation Medal.

His interests included the Civil War and horses. He was a director of the Great Falls Pony Club and Bull Run Hunt and a member of Dranesville United Methodist Church in Herndon.

His marriage to Madeleine C. Mayher ended in divorce.

Survivors include his wife of 32 years, Dorothy T. Ganahl of Great Falls; three children from his first marriage, Joseph Ganahl Jr. of Mokuleia, Hawaii, Constance Hale Ganahl of Oakland, Calif., and Susan T. Ganahl of Mililani, Hawaii; a daughter from his second marriage, Katherine T. Ganahl of Reston; and two granddaughters.