Jon Douglas Trefz, a longtime resident of Vermillion, SD, died Feb. 13, 2023, with his family by his side. Among Jon’s last words to his loved ones were these, “This life has been such a good life.” Jon was born Nov. 6, 1952, in Eureka, SD to Henry and Lydia (Heil) Trefz. As a small child, his family moved from Mound City, SD to Roscoe, SD where he attended Roscoe Public School. Many of his…