Mark Jason Willoughby, 50, of Hermantown passed away unexpectedly but peacefully at home on Monday, March 19, 2018. He was born January 3, 1968, in Edina, MN to Janice & James Willoughby. Mark graduated from Burnsville High School, the University of Minnesota in Minneapolis with a degree in Electrical Engineering, and an MBA from Purdue University. He worked as an Electrical Engineer and in management at Enbridge Energy for over 27 years. At age 16 he met Jennifer Mattson in Owatonna, the love of his life, and they had been together ever since. They had 34 wonderful years together. Together they were raising 3 amazing, strong boysAlexander (23 of Scottsdale, AZ), Benjamin (21 of Duluth), and Luke (10 of Hermantown). Mark loved to travel, play his many guitars, spend time on the lake, ski with the kids, and was active in his church praise band, but the most important thing in his life was always his family. He was so very, very proud of his boys. Mark had an awesome sense of humor and was well respected by all who knew him. He was preceded in death by his grandparents, father; and sister, Heather Willoughby. He is survived by his wife, Jennifer (Mattson) Willoughby of Hermantown; his boys, Alex, Ben, & Luke; mother, Janice (Gibis) Willoughby of Sioux Falls, SD; brothers, Vince (Sheila) Willoughby of St. Louis, MO, Brock (Alisa) Willoughby of Sioux Falls, SD; all of Jennifer’s family; nieces and nephews, Hunter, Maxwell, Brendan, Alivia, Sam (Shelly), Max, Abby, Andrew; and many aunts, uncles, and friends. Visitation will be 5-7PM Friday, March 23, 2018, visitation will continue, 3PM, Saturday until the funeral service starting at 4PM, at Peace in Christ Lutheran Church, 5007 Maple Grove Rd, Hermantown, MN 55811. Arrangements by Dougherty Funeral Home, 218-727-3555.