Marlon "Lonnie" Thielsen, 79, of Flandreau, SD, passed away Wednesday, July 31, 2019 at Riverview Healthcare Community, Flandreau. Lonnie was born February 21, 1940 at Flandreau, SD, to Kermit and Bethel (McFarland) Thielsen. He attended Tidd Country School and graduated from Flandreau High School in 1958. Lonnie attended SDSU in Brookings for one year. He married Nina Sue Petersen on March 18, 1960 in Flandreau where they raised two sons. They farmed north of Flandreau until 2000. Lonnie was a member of the United Methodist Church. He was an active 4-H leader and Friend of 4-H, held sheep showing clinics at his farm for FFA and 4-H, was a FFA honorary chapter farmer, served on the Spring Creek Township Board for several years, and served on the SD Game, Fish & Parks Board for seven years. Lonnie enjoyed hunting, fishing and trapping and built a fishing pond for his family's enjoyment. He was well known for his sense of humor and practical jokes. Lonnie's pride and joy were his grandchildren and great-grandchildren.

Lonnie is survived by his wife Nina Sue; son Brian (April), Flandreau; daughter-in-law Becky Hoogenakker, St. Michael, MN; seven grandchildren, Aaron (Bethany); Travis (Jessica); Tyler (Christa); Anissa (Roope) Reko; Kara Thielsen; and Melissa Boetger; Lee (Maggie) Schenkel; 13 great-grandchildren, Sierra, Blake, Rory, Noelle, Erica, Marlayna, Jocelyn, Kaylee, Christopher, Floyd, Kaycie, Jonathan, Sebastian, and several nieces and nephews. Lonnie was preceded in death by his son Brad, his parents, sister Karen Eikmeier, and an infant sister.

Funeral services will be 2:00 pm Saturday, August 3, 2019 at the United Methodist Church, Flandreau. Visitation will be 5:00 – 7:00 pm Friday with a 7:00 pm prayer service at Skroch Funeral Chapel, Flandreau.