Mark was born in Scobey, Mont. to Lillian (Tymofichuk) and JR McKiernan in 1953. He graduated from Panhandle High School in 1971.
Survivors include his wife, Rae Lynn McKiernan; three daughters, Andi and husband, Matt Wiseof Portland, Ore., Sheri and husband, Daniel Santiago of Benson, Ariz., and Tina and husband, Chris Branscum of Highlandville, Mo.; two sons, Trent McKiernan of Cave Junction, Ore. and Luke McKiernan and wife, Rachel of Portland, Ore.; two sisters, Betty Jo Smith of Amarillo and Patty Dauer of Nipomo, Calif.; eight grandchildren, Mac and Bodi Wise, Chelsea, Raegan, Marshall and Sydney Branscum; Shanelle and Loreine Santiago; and numerous nieces and nephews.