(Undated) -- A burgeoning Oregon burger franchise is expanding into Washington's Puget Sound. Officials with Killer Burger say they're moving ahead with plans to open new stores in Tacoma, Puyallup and Olympia over the next five years, this after opening their first location in Portland in 2010. The brand reportedly has been hailed as "Best Burger" in multiple West Coast markets over the past five years. Company sources say the new deal doubles their commitment to serving world-class burgers at 12 locations in Washington, Oregon and Idaho.