The Holy Grail of Pacific Northwest soccer: The Cascadia Cup

One of several 'derby cups' in MLS

While Saturday night will be an historic moment for Vancouver Whitecaps FC with the club's final match at Empire Field, the visit of Interstate 5 rivals Seattle Sounders FC will also be the latest chapter in a derby competition that has gained increasing interest across North America.

When Whitecaps FC and Portland Timbers joined Major League Soccer this season, the supporters of both clubs renewed a rivalry with fans from Seattle that traces its origins back to when all three clubs were members of the United Soccer Leagues First Division (USL-1) in 2004. Known for the region of North America that Vancouver, Seattle, and Portland represent, the Cascadia Cup was created by the supporters of the 'Caps, Sounders FC, and the Timbers. It is awarded to the club that has the best head-to-head record in regular season matches between their Pacific Northwest rivals.

Going into this year's Cascadia Cup competition, Whitecaps FC are the most successful of the three clubs, having won the trophy in 2004, 2005, and 2008. Before joining MLS in 2009, the USL-1 Sounders were cup winners in 2006 and 2007, while Portland are the current holders after winning the title in 2009 and 2010 when the trophy was only contested between the 'Caps and the Timbers at the North American second division level.

(VIDEO) WHITECAPS FC - 2008 CASCADIA CUP WINNERS

With two matches left in the 2011 Cascadia Cup, Seattle currently lead the standings with five points from three matches played (1W-0L-2D), while the Timbers are second with four points from three matches played (1W-1L-1D). Whitecaps FC are third after claiming one point from two games played (0W-1L-1D). That leaves Vancouver in need of home victories over Seattle and Portland in the hopes of claiming a fourth title this season, while Sounders FC can win the trophy for the first time in four years with a victory at Empire Field. Should Vancouver and Seattle draw this weekend's match, Portland will have an opportunity to defend their Cascadia Cup title with a win in Vancouver on Sunday, October 2.

The Cascadia Cup rivalry has been much anticipated in MLS this season, but it is far from the only 'derby cup' that is contested each season by clubs in the league. By season's end, nine other fan-based trophies will be awarded.

FC Dallas (formerly Dallas Burn) and Chicago Fire have contested the Brimstone Cup since 2001. FC Dallas have won the cup seven times, while the Fire have only won the cup on one occasion. This year's trophy will be awarded next month after both clubs drew their first league meeting on opening day (March 19). The Texas outfit were able to retain the Lamar Hunt Pioneer Cup versus Columbus Crew this season, with the trophy first created in 2007 in honour of former Dallas and Columbus owner Lamar Hunt. FC Dallas will also look to add a replica 18th century mountain howitzer cannon named 'El Capitan' to their trophy cabinet by winning their third Texas Derby when they host state rivals Houston Dynamo on Saturday. Both clubs drew their first encounter in Space City back in May.

As for Columbus, not only did they miss out on the Lamar Hunt Pioneer Cup, they also conceded the Trillium Cup for the first time since the creation of the two-club derby competition with Toronto FC in 2008. Named after the official provincial and state flower of both Ontario and Ohio, the Crew won the Trillium Cup during the first three years it was contested before TFC won the trophy this season with an historic 4-2 away win over Columbus on September 10. New York Red Bulls may have had a difficult season to this stage, but they were able to retain the Atlantic Cup after splitting their two league games with D.C. United. As for the Rocky Mountain Cup, Real Salt Lake have the upper hand over rivals Colorado Rapids going into the decisive game at Dick's Sporting Goods Park next month. RSL have won the trophy the last four seasons.

On the west coast, three other derbies are contested by MLS clubs. Sounders FC and San Jose Earthquakes will settle the Heritage Cup at Seattle's CenturyLink Field next month, while top MLS club LA Galaxy edged San Jose to one of the oldest rivalries in MLS by winning their 10th California Clasico title this season. The Galaxy are also in the driver's seat to win a fourth-straight Honda SuperClasico title versus fellow tenants at The Home Depot Center in Chivas USA. Also known as 'El Clasico Angelino' or 'LA Derby', the rivalry is considered as the only "true" local derby in the league since it came into being in 2005.