Ronald Dean Koester, 90, of Idaho Falls, passed away on April 5, 2026, at Teton Healthcare of Cascadia.

Funeral services will be held at 1:00 p.m., Monday, April 13, 2026, at the First Presbyterian Church, 325 Elm Street, Idaho Falls. The family will visit with friends and family from 6-8:00 p.m., Sunday, April 12, 2026, at Coltrin Mortuary, 2100 First Street, Idaho Falls, and one hour prior to services at the church. Interment will be at Fielding Memorial Park Cemetery. Online condolences may be sent to www.coltrinmortuary.com.