James C. McClellan, 69, retired chief forester of American Forest Products Industries, died Tuesday at Fairfax Hospital after a heart attack.

He had joined the AFPI (now the American Forest Institute) in 1946 and became chief forester two years later. He retired in 1970. While there, Mr. McClellan helped develop the nation-wide tree-farm program, promoting better forest management of privately owned timberland.

He also traveled extensively, getting local organizations to work for forest fire prevention under the "Keep-America-Green" program.

Born in Hannibal, N.Y., Mr. McClellan graduated from the N.Y. State College of Forestry at Syracuse University in 1929. After a variety of jobs, he became a supervisor in the Civilian Canservation Corps.

He then was a timber management specialist with the U.S. Forest Service in the Allegheny National Forest in Pennsylvania and the Monongahela forest in West Virginia.

Mr. McClellan came to Washington in 1944 as assistant forester for the National Lumber Manufacturer's Association.

He is survived by his wife, Florence, of the home in Fairfax; two sons, James P., of Alexandria, and Gary S., of Phoenix, Ariz.; a daughter, Jane Boyce, of Annandale, and four grandchildren.

The family suggests that expressions of sympathy may be in the form of contributions to the Fairfax Rescue Squad.