Oliver R. Montagne

Oliver R. Montagne, 88 of Sioux City, formerly of Jefferson, South Dakota, passed away on Thursday, January 30, 2025 at a nursing facility. A Mass of Christian Burial will be at 11:00 a.m. Tuesday, February 4th at St. Peter’s Catholic Church in Jefferson, South Dakota with Father Joe Vogel as Celebrant. Burial will follow at St. Peter’s Cemetery adjacent to the church. Visitation, with family present, will be one hour prior to Mass at the church. Online condolences may be offered to the family at www.meyerbroschapels.com Meyer Brothers Colonial Chapel is assisting with arrangements.

Oliver was born on December 13, 1936, in Sioux City, IA, the son of Ralph and Lillia (Chartier) Montagne. He graduated from Heelan High School in 1954. He completed a two-year course in animal husbandry at the South Dakota State University (SDSU). While at SDSU, Oliver enrolled in the ROTC and was a member of the ROTC Rifle Team. He won multiple Rifleman awards. After college, Oliver went on to serve full-time in the U.S. Army. He returned home and farmed while working additional full-time jobs in his younger years. Oliver farmed until his retirement. 

On November 28, 1964, Oliver married the love of his life, Mary Kirwan, at the Immaculate Conception Catholic Church in Sioux City. They raised their six children on their century family farm; Tim, Jackie, Therese, Britt, Breck, and Molly. 

Oliver was very active in his community. He was kind, respectful, and generous to all he knew. He was strong in his Catholic faith and was a good, trusting man. Oliver served on the St. Peter’s Parish Board, Jefferson School District School Board, and Jefferson Farmers’ Elevator Board. Oliver served seven years as the Director of the Union County Pork Producers Council. He was a lifelong member of the Knights of Columbus and the South Dakota Pork Producers. Oliver’s passions were farming, and spending time with his family. 

Oliver is survived by his loving wife, Mary; children: Tim Montagne, Jackie Montagne (Gene Hacker), Therese Spehar (Tom), Britt Montagne, Breck Montagne, and Molly Ramlo (Dean); grandchildren: Alexa, Jace, Kayla, Amanda, Kaitlyn, McKenzie, Addison, Jacob, and Caleb; and great-grandchild: Tatum. 

He was preceded in death by his parents; sister, Grace Port; grandson, Justin Montagne; father-in-law, Art Kirwan; mother-in-law, Edna Kirwan; and brother-in-law, James Port.

The family wants to thank The Heritage at Northern Hills staff for their kindness, compassion and excellent care while Oliver resided at their facility.  An additional thanks to the VA Admin staff and St. Croix Hospice, for their assistance.