John was born Oct. 17, 1916, west of Hull, the son of Ralph J. and Jennie (Vande Weerd) Kooiker. He attended several rural schools in northwest Iowa and Jones County, S.D., graduating from the eighth grade in O'Brien County, Iowa.
On June 16, 1939, he married Esther L. De Koster, the daughter of Dick and Ida (Bregman) De Koster, in Hull.
They made their home in Hull, where he worked for various road contractors, before forming his own company in 1949. In 1970, he founded Kooiker, Inc., with his sons, Clayton and Calvin. They operated out of Hull and Le Mars, doing bridge and culvert construction and excavation. He took great satisfaction in his work, operating his dragline to dig drainage ditches and farm ponds until he was 86 years old.
He also used his skills in support of community activities, such as preparing the ice skating rink, assisting with swimming pool construction, and building bluebird houses for the Sioux County Conservation Board.
John and Esther often traveled in the winter to California, Texas, Florida, and Hawaii, as well as points in between. They also enjoyed attending their grandchildren's school, sports and other activities.
Mrs. Kooiker died March 9, 1998, in Hull, after more than 58 years of marriage. In August 2004, John moved to Le Mars, where he became a resident of Park Place Estates. In May of 2006, he transferred to Brentwood.
He was a member of the American Reformed Church in Hull, where he served on the consistory as a deacon and was president of the Men's Brotherhood for some time.
Survivors include his twin sons and their wives, Clayton and Janice Kooiker and Calvin and Dixie Kooiker, all of Le Mars; four grandchildren, Stacy (Michael) Kooiker Brostoski, of Casper, Wyoming, Daniel Kooiker, of Le Mars, Jason (Amy) Kooiker, of Sioux Falls, S.D., and Jared (Ann) Kooiker, of La Mesa, Calif.; two great-grandchildren, Ashley and Autumn Kooiker, of Le Mars; two sisters, Jennie Vander Sloot, of Lyons, Kan., and Maxine Napier, of Muskogee, Okla.; three brothers, Henry Kooiker, of Bellflower, Calif., Arthur (Mina) Kooiker, of Sheldon and Elmer (Celia) Kooiker, of Missouri Valley; and many nephews and nieces.
In addition to his parents and wife, he was preceded in death by a sister, Harriet Van Batavia; a brother, Edwin Kooiker; two sisters-in-law, Esther (Boote) Kooiker and Virginia (Sipma) Kooiker; and three brothers-in-law, Jake Van Batavia, Ed Vander Sloot, and Ray Napier.
There will be a memorial service on Friday, March 2, at 10:30 a.m. at the American Reformed Church, 911 First Street, Hull. The Rev. Steven Bierly will officiate. Interment will be prior to the service at the Hope Cemetery in Hull. Visitation will be after 2 p.m. Thursday, with the family present from 2 to 7 p.m., at the Oolman Funeral Home in Hull.
Memorials may be directed to the American Reformed Church.
Expressions of sympathy may be made at at www.oolman.com.