Arthur M. Sowder, a state and federal forestry official for 37 years, died of Parkinson's disease Nov. 21 at Montgomery General Hospital. He was 77.

Born in Washburn, Wis., Mr. Sowder earned master's degrees in forestry from both the University of Idaho and Yale University. After receiving the first extension forester at Idaho University. He spent four years in that capacity before joining the forestry faculty there.

He later received a scholarship to Yale and earned his second master's degree in 1937.

A year later he moved here and worked with the federal extension service of the Department of Agriculture where he was responsible for forestry in all states west of the Mississippi River. He retired in 1964 as chief extension forester.

Mr. Sowder was the author of the 1952 Government Printing Office publication. "Christmas Trees - The Tradition and the Trade."

His hobby was dowsing, which is the art of detecting underground water flow by means of a Y-shaped stick that twists in the hand and points to hidden water. He was one of the first members of the American Dowsing Society, and once said that he felt the technique is probably related to static electricity.

Mr. Sowder served two years as chairman of the Washington branch of the Society of American Foresters and was chairman of Epsilon Sigma Phi, an organization of the federal extension service.

Survivors include his wife, Rose P., of Sandy Spring; three daughters, Sandra S. Mitchell, of Pa Plata, Md., Cynthia S. Picha, of Camarillo, Calif., and Diane S. Thompson, of Potomac; a sister, Dorothy S. Henry, of Colfax, Wash.; three brother, Kenneth I., and Charles G., both of Coeur d'Arlene, Idaho, and Raymond W., of Boise, Idaho, and three grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the Memorial Planting Fund of St. Luke's Lutheran Church in Silver Spring.