Clayton Kooiker, 83, of Le Mars, Iowa, passed away surrounded by family on Tuesday, April 21, 2026, at his home.

Celebration of Life Service will be at 2:00 p.m. on Saturday, May 9, 2026, at Rexwinkel Funeral Home in Le Mars. Reverend Paige McGrath of Living Faith Lutheran Church in Le Mars will officiate. Clayton donated his body to the University of South Dakota School of Medicine. Burial will be at a later date at Memorial Cemetery in Le Mars with military honors provided by the Wasmer American Legion Post 241 of Le Mars. Visitation with the family present will be from 1:00 p.m. until service time on Saturday at the funeral home. Expressions of sympathy can be extended to the family through www.rexwinkelfh.com.

Memorials can be made to your local hospice provider in memory of Clayton.

Clayton Dale Kooiker was born on December 12, 1942, in Hull, Iowa, to John and Esther (De Koster) Kooiker. He graduated from Boyden-Hull Community School in 1961. He then served in the United States Army from 1962 to 1964 in the 38th Military Police Battalion in Kornwestheim, Germany. Clayton attended Westmar College and earned a BA in Business Administration.

While attending Westmar, Clayton met Janice Dunbar. They were united in marriage at Myra Valley EUB Church in Valley County, Nebraska in 1966.

Clayton operated Kooiker, Inc with his twin brother, Calvin, for 51 years. The company built and repaired bridges and culverts in several counties in northwest Iowa.

Clayton enjoyed operating heavy equipment, flying and giving airplane rides, and taking road trips on his motorcycle or in his classic car. He enjoyed boating and taking family vacations and made new friends wherever he went. Clayton was known for baking hundreds of apples pies and giving them to friends.

Clayton attended Living Faith Lutheran Church in Le Mars and was a member of the Wasmer American Legion Post 241 of Le Mars.

Clayton is survived by his wife, Janice; a daughter, Stacy; a son, Daniel; and a twin brother, Calvin.

He was preceded in death by his parents, John and Esther.