James "Jim" Paul Keener

James (Jim) Paul Keener, 79, of Salt Lake City, Utah, passed away under hospice care on April 29, 2026. He was a beloved spouse, father, and grandfather, a gifted and methodical teacher and mentor, and a devoted friend. He will be sorely missed.

Born in Lancaster, Pennsylvania on November 11, 1946, Jim spent his early life on a farm with his parents, Helen and Paul, and little sister, Kathy. On his 11th birthday, his parents forced him to move to Tampa, Florida. There, he attended and graduated high school, met a beautiful girl named Kris. They married on June 29, 1968.

Jim earned his B.S. in Mathematics at Case Western Reserve and his Ph.D. in 1972 from CalTech (California Institute of Technology). Jim spent his career at the University of Utah in a mathematical biology group. Professionally, he was a pioneer and internationally renowned in the field of mathematical physiology, studying the math of biological functions of the body. Over the course of his career, Jim mentored 31 PhD students through their Doctoral Dissertation and Defense. He also published over 90 publications as well as 3 books.

But, few things brought Jim more joy than a conversation with a student wrestling with a difficult problem. He poured himself into the mentorship of PhD and applied mathematics students alike, and the impact of his investment followed them long after their studies ended. Jim kept in touch with many of those he mentored throughout their professional lives, a testament to how genuinely he cared — not just about their work, but about the people they were becoming.

Through his entire life, Jim was a committed Christian, taking active teaching and leading roles in various parts of church life. He is well remembered for the deep, lasting relationships he forged with those he taught through his long-standing Sunday School class and the publication of a book based on the life of David. He invested personally in each person who sat under his teaching, and many grew not only in their faith but in a close bond with Jim himself because of the time and care he poured into them.

If you knew Jim, you knew he loved to be outside and a good day was any day he could be in the mountains. And there was never any bad weather, except maybe rain. Throughout his life, he was very active: fishing, hiking, skiing, biking, playing squash, walking. His favorite spot was a little cabin in Big Cottonwood canyon. These pursuits were made richer by the people who joined him. Jim loved sharing the outdoors with friends and family and was a natural mentor in these settings, as generous with his knowledge of a good trail as he was with anything else.

Jim lived a full life, especially in his last years, despite on-going cancer and cancer-related treatments. No matter what disease took from him, he was able to find new ways to fill his life with the outdoors, creativity, rigorous research, and community. Until the very end, he maintained a fierce will to fight disease and a thankful and graceful spirit.

Jim is survived by his wife of 58 years, Kristine; his kids Sammy (Eric) Beuker of Grand Rapids, Michigan and Jay (Leslie) Keener of Summit Park, Utah, and his 6 grandkids Josh, Kai, Niko, Mali, June, and Kilian, all of whom he was exceptionally proud.

He was preceded in death by his parents, Paul and Helen (Gibble) Keener and sister, Kathy Payette. Their family reunion was 35 years in the making.

Services for Jim will be on Saturday, May 9 at Larkin Sunset Lawn (2350 E. 1300 S, Salt Lake City, Utah 84108). Visitation with the family will be from 9:30-10:45. The Celebration of Jim’s life will take place at 11 with a graveside service for family and close friends immediately following. But because this is a celebration of a life well lived, there will be a time for mingling and story sharing outside after the service. Because Jim would hate that we are all inside on a Saturday, guests are encouraged to dress for a hike and then go on one to celebrate him in the Creation that he loved.

In lieu of flowers, donations can be made in Jim’s honor to Discovery Institute, with whom Jim was working to bring scientific accuracy to the Intelligent Design movement. Gifts can be made at discovery.org/id/donate in honor of Jim Keener.