The Seattle Sounders play the Vancouver Whitecaps today. If they win or draw the game they will clinch the Cascadia Cup. The Cascadia Cup was made official in 2004 by the fans of the Portland Timbers, Seattle Sounders and Vancouver Whitecaps, but its history goes even further back.
Before the Cascadia teams were a part of Major League Soccer they played each other in the North American Soccer League and the United Soccer League. Even then, fans would drive the I-5 corridor to attend sell-out games with their banners and voices primed for cheering.