Spencer J.H. Brown Sr., 79, a veteran volunteer fire fighter in Montgomery County and former president of the Maryland State Firemen's Association, died Sunday at Montgomery General Hospital. He had been injured 10 days earlier in a fall at his home in Sandy Spring.

Born in Unity, Md., Mr. Brown had moved to the Sandy Spring area in 1920. In 1930, he built the Sandy Spring Gulf service station and operated it until 1972, when he sold it and retired.

His volunteer fire and rescue work began in 1924, when he helped to organize the Sandy Spring Volunteer Fire Department. He served as its chief for 16 terms until the late 1950s, and was president of the department for two terms in the late 1960s.

Mr. Brown also served four terms as president of the Montgomery County Fire and Rescue Association. He at one time was an adviser to then Maryland Gov. J. Millard Tawes on fire and rescue matters.

He also taught in the University of Maryland fire service extension program and had helped to set up volunteer fire departments in Laytonsville, Damascus, Clarksville and Mount Airy.

In 1974, he received a certificate of distinguished citizenship from Gov. Marvin Mandel for his 50 years of service in fire fighting and rescue programs.

He is survived by his wife, Mary, and a daughter, Virginia, both of the home; another daughter, Helen K. Boone, of Gaithersbury; a son, Spencer J.H. Jr., of Sandy Spring, three grandchildren and eight great-grandchildren.