Dorothy Clark Prettyman, 74, a lifelong area resident who was active in civic, church and service organizations, died Wednesday at the University Nursing Home in Wheaton. She had Parkinson's disease.

Mrs. Prettyman, who lived in Rockville, was born on the old Sycamore Spring Farm near the Four Corners area of Silver Spring. She attended Georgetown Visitation Preparatory School inf Washington and Notre Dame Academy in Baltimore.

She worked for the Montgomery County government before her marriage in 1931 to Charlie W. Prettyman, now a retired officer of the Credit Bureau Inc.

Mrs. Prettyman was active in the American Red Cross and served as a Cub Scout den mother. She also was active in PTA activities at the Woodside Elementary School and Montgomery Hills Junior High School in Silver Spring.

She was a former member of the altar guilds of Grace Episcopal Church in Silver Spring and Christ Episcopal Church in rockville. She was a member of the Current Comment Club in Silver Spring and the Georgetown Visitation Alumnae Association.

Mrs. Prettyman worked part-time as a free-lance heraldic artist.

Besides her husband, of the home, survivors include two sons, Forrest J., of Arlington, and Edward C., of Rockville, and three grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the American Parkinson Disease Association at Georgetown University Hospital.