Montana Streit had a goal and an assist to lead the way for the Mils while Logan Foster and Taylor Elmy also scored.
Matthew Jones had the lone goal for the Terriers.
Mils netminder Colby Entz earned his 6th victory against Yorkton making 28 saves on 29 shots while Ben Laidlaw took the loss in the Terrier crease making 27 saves.
The Mils next game will be on Wednesday night when they host the Estevan Bruins. GX94 will broadcast the game with Yorkton dodge Junior Hockey, pregame 7:20 pxp at 7:30 while the Terriers wrap up their 2017/18 season on Friday night when they host the Weyburn Red Wings.