Leonard O. Nelson was born January 26, 1929 at Akron, IA to Anders and Mary (Groon) Nelson. He grew up on the family farm near Beresford and attended a one room country school. He and his brother Robert were one of two sets of twins born to the Nelson family. In 1944 he moved with his family to Parker where he graduated from high school in 1947. He then attended South Dakota State University graduating in 1952. He began working in Aberdeen as the Assistant County Extension Agent for Brown County. On June 15, 1958 he married Irma Lunzman. They made their home in Aberdeen and then Ipswich where he worked as County Extension Agent. In 1965 they moved to Maryland where he pursued his Masters Degree. After returning to South Dakota they moved to Lake Andes where he was the County Extension Agent and then became involved in water resources with a rural water district and consulting engineering firm. They moved to Mitchell where he was the Davison County Extension Agent until 1984 and then worked as an adjuster in the crop insurance industry until retiring in 1999.
He was a member of Zion Lutheran Church and served on the Board of Elders and was also Congregational Chairman.
Leonard enjoyed hunting, fishing, wintering in the Mesa, AZ area for the past many years and visiting with family and friends over a cup of coffee.
He is survived by his wife Irma, one son, Stuart Nelson and wife, Stacey of Mina, two sisters, Audrey Versteeg of Brandon, Arliss Gortmaker and husband, Arnie of Monroe and two grandchildren, Emelia and Isaac Nelson.
He was preceded in death by his parents, three brothers, Arnold, Lowell, his twin brother, Robert, one sister, Martha Bollweg and granddaughter, Sarah Nelson.