Darla Kaye Koisti of Lake Norden, South Dakota passed away on October 4th, 2025 at the age of 82. A Visitation will be held from 12:00 pm to 2:00 pm at the Lake Norden Community Center on Monday, October 20, 2025. Interment will be held at a later date.

Darla was born on April 17, 1943, the daughter of Maynard and Lilace (Pearson) Kastein. She was united in marriage on June 21, 1964, to Sheldon E. Koisti. A generous and charitable woman, Darla was very involved in her local community. She was a longtime member of Trinity Lutheran Church in Lake Norden. Throughout the years, Darla served on the church council and Christian Education Committee, as well as taught Sunday school and sang in the church choir. She kept the books for the church, the city, Pheasant Lanes in Hayti, and Norden Motor. Darla served as city treasurer and on the city council for Lake Norden, as well as on the elections board. She was also very involved with Meals on Wheels and helped deliver meals for many years.

Some of Darla's hobbies included bowling, golfing, playing cards and going to the casino.

Darla is survived by her sister Dorene Lemme, her brother Darryl (Gloria) Kastien and sister-in-law Trice Ann Kastein, her children Shelley Jensen (Dick), Barbara Halonen (Rus) and Richard Koisti (Amy), 5 grandchildren, Claire Jensen, Matthew Jensen, Chelsea Halonen, Becca Halonen, Courtney Koisti and 2 great grandchildren.

She was preceded in death by her husband Sheldon Koisti, parents Maynard and Lilace, brother Larry Kastein and brother-in-law Barry Lemme.