TULALIP — The Seattle Premium Outlets on the Tulalip Reservation have done such good business that the Simon Property Group plans to expand their retail space by an additional 100,000 square feet.

According to Michele Rothstein, a spokesperson for the Premium Outlets division of Simon, the Seattle Premium Outlets’ existing 120 stores produce sales in excess of $700 per square foot, making them one of the group’s most productive centers.

While Rothstein declined to speculate on how many new stores would be added during the expansion, or which ones they would be, she anticipated that the expansion would be complete in 2013, bringing the Seattle Premium Outlets’ total retail space to approximately 540,000 square feet.

The Seattle Premium Outlets were built in 2005 and include Adidas, Ann Taylor, Banana Republic, Calvin Klein, Coach, Cole Haan, DKNY, J.Crew, Kenneth Cole, Lacoste, Nike, Polo Ralph Lauren and Tommy Hilfiger.

Rothstein attributed the stores’ sales success to shoppers coming from the local area, throughout the Puget Sound region and even from Canada,. She predicted that the Cabela’s store currently under construction at Quil Ceda Village, just south of the Seattle Premium Outlets and the Tulalip Resort Hotel and Casino, would also draw customers to those stores.

“The Tribes are very excited about this,” Tulalip Tribal Chair Mel Sheldon Jr. said. “It furthers our goal of making this a destination resort and gives shoppers even more choices.”

Sheldon credited his predecessors and peers on the Tribal Board with laying the groundwork for the Tribes’ ongoing economic expansion, which he hopes will benefit the Tribes’ neighbors and Snohomish County as a whole.