It was represented by teams based in British Columbia, Montana, Oregon and Washington.
Those teams include the: Aberdeen Black Cats (1905, 1917), Bellingham Gillnetters (1905), Everett Smokestackers (1905), Spokane Indians (1905–1917), Vancouver Horse Doctors (1905, 1907), Victoria Legislators (1905), Butte Miners (1906–1908, 1916–1917), Grays Harbor Lumbermen (1906), Tacoma Tigers (1906–1917), Seattle Siwashes (1907–1908), Grays Harbor Grays (1908–1909), Vancouver Beavers (1908—1911, 1914, 1916–1917), Portland Colts (1909, 1912—1914), Seattle Turks (1909), Seattle Giants (1910—1917), Portland Pippins (1911), Victoria Bees (1911–1915), Vancouver Champions (1912, 1915), Vancouver Bees (1913), Ballard Pippins (1914), a Great Falls, Montana team (1916) and Great Falls Electrics (1917).
In 1906, the Tacoma Tigers finished in first place and in 1907 the Aberdeen Black Cats took the crown.
The Vancouver Beavers finished in first place in 1908 and again in 1911 and 1914, the Seattle Turks in 1909 and the Spokane Indians in 1910.
In 1915, the league played its only official playoff, which matched the first-place Seattle Giants against the second-place Tacoma Tigers.