The Timbers and Whitecaps have antagonistic roots dating to the days of the original North American Soccer League beginning in 1975.

[3] The rivalry regained steam as Portland and Vancouver clashed in crucial, and often physical matches during the late 2000s, with the clubs facing each other in memorable playoff duels in 2007, 2009, and 2010.

However, individual matches between the sides have been just as intense as any rivalry in the league, such as when Portland defeated Vancouver in a brutal two-game playoff series on their way to winning the 2015 MLS Cup.

[8] Both the Timbers and the Whitecaps achieved success in the beginning years of the league, with Portland winning the regular season title in 1975 and making the Soccer Bowl while Vancouver won the championship in 1979.

In 2004, fan-based organizations supporting the Portland Timbers and Vancouver Whitecaps as well as the Seattle Sounders sponsored the creation of a two-foot-tall silver cup to be awarded annually to the club that finishes with the best record in the season series between the three rivals.

The Portland-Vancouver rivalry reached new heights near the end of the 2000s after Portland knocked Vancouver out of the USL playoffs in 2007, only for the Whitecaps to return the favor twice, delivering a death blow to the Timbers' postseason runs in both 2009 and 2010.

In the 2009 season, Portland was the top-ranked club in the league but fell to Vancouver in a dramatic two-game series that the Whitecaps won 5-4 on aggregate.

This was the first time Portland had advanced past the first round of the A-League or USL playoffs, in what was described as "an intense and offensive contest between the Northwest rivals".

[14] In 2009 and 2010, supporters of the Timbers and Whitecaps decided to continue the Cascadia Cup without the Sounders while playing in the USL, after Seattle moved to Major League Soccer in 2009.

Timbers and Whitecaps supporters voted to only included regular season USL-1 matches played between the teams and Portland won the cup for the first time.

Vancouver won the first game of the two-game playoff series 2-1 at Swangard Stadium in Burnaby, BC, meaning that the Timbers would need to win at home in order to advance.

After the first game tied 0-0 at Portland's Providence Park, the Timbers won the return match at BC Place 2-0 on goals by Fanendo Adi and Diego Chara, advancing to the Western Conference Finals.

Members of the supporting groups between the two clubs even jointly celebrated together after Vancouver eliminated Portland from the 2010 USL Playoffs due to the shared move to MLS the next year.