Ruth S. Koistinen, 85, of Lake Norden, SD, passed away on Thursday, March 19, 2020, at the nursing home in Clear Lake, SD, at the age of 85. Due to health precautions, private family Funeral Service will be held at 1:00 pm Monday, March 23, 2020, at the Old Apostolic Lutheran Church, in rural Lake Norden. A public viewing, without family present will be from 10:30 am to 11:30 am, Monday at the church. Geise Funeral Home is assisting the family with arrangements.

Ruth Sylvia Rivers was born in Brainerd, MN, on July 24, 1934 the daughter of W. Gerhard and V. Sylvia (Pikkaraine) Rivers. She was raised and attended school in Brainerd and graduated from Brainerd High School in 1952.

Ruth worked in the bank setting and spent some time living in Minneapolis, MN, before being united in marriage to Byron Koistinen on September 27, 1958, at Lake Norden, SD.

They lived in Watertown, SD, for a short time before moving to Sioux Falls, where her husband was employed by the US Post Office. In 1977, they moved to a farm near Hayti, SD. In 1990, they relocated to Texas, where they resided until Byron's death in 2014. For the past five years, Ruth has been a resident at The Homestead Assisted Living in Lake Norden.

Ruth was a lifelong member of the Old Apostolic Lutheran Church.

Ruth is survived by her son, Anthony Koistinen, of Aledo, TX; daughter, Kimberly, (Delaney) McGuirk, of Watertown, SD; her brothers, James (Greta) Rivers, of Maple Plain, MN, Carl Rivers, of Weatherford, TX, David (Ruth) Rivers, of Woodland, WA; her sisters, Mary Ann Sarkinen, of Buffalo, MN and Helen Sarkinen, of Battle Ground, WA; sister-in-law, Lillian Koistinen, of Hayti, SD and a host of relatives and friends.

She was preceded in death by her parents, and husband, Byron.