Northwest League of Professional Baseball (or simply the Northwest League or NWL) is a Class A Short Season minor league in the northwest United States and western Canada. The NWL's short season starts in mid-June, after major league teams have signed their amateur draft picks to professional contracts, and ends in early September. All eight teams are affiliated with a major league team.
The Northwest League (or the
Northwestern League) has existed in various forms since 1890, and has been in its current incarnation since 1955. The current NWL is the descendant of the  Western International League (WIL), a Class B league from 1937 to 1951 (with a stoppage during World War II) and Class A from 1952 to 1954. The league reformed as the Northwest League and dropped to Class B for the 1955 season.  
The WIL had ten teams in its final season, with four in Canada. In 1955, the Northwest League was formed, with seven charter teams:
Salem Senators, Eugene Emeralds, Yakima Bears, Spokane Indians, Tri-City Braves, Wenatchee Chiefs, and Lewiston Broncs.  During its fiftieth season in 2004, five of the seven original cities were in the league. The Northwest League switched to the short season schedule in 1966,  with only four teams,   and expanded to six in 1970.   
The start of the 2020 season was postponed due to the
COVID-19 pandemic in North America before ultimately being cancelled on June 30.  
Current team locations: North Division South Division
(2017)  Average (2017)  North
Tri-City Dust Devils
San Diego Padres
Toronto Blue Jays
Vancouver, British Columbia
Scotiabank Field at Nat Bailey Stadium
Ron Tonkin Field
San Francisco Giants
Current team rosters
League champions have been determined by different means since the Northwest League's formation in 1955. Except for 1956, 1960, and from 1966 to 1973, all seasons have ended with playoffs to determine a league champion.
Spokane Indians and Yakima Bears have each won 8 championships, the most among all teams in the league, followed by the Boise Hawks and Eugene Emeralds (6). 
Former Northwest League teams (1955-)
Cities that have hosted NWL teams
Boise: 1975-76, 1978, 1987- (34 seasons) Lewiston: 1955-1974 (20 seasons)
Bend: 1970-71, 1978-94 (19 seasons)
North Bend: 1970-72 (3 seasons)
Eugene: 1955-68, 1974- (59 seasons)
Hillsboro: 2013- (8 seasons)
Keizer: (Shared with Salem) 1997- (23 seasons)
Medford: 1967-71, 1979-99 (26 seasons)
Portland: 1973-77, 1995-2000 (11 seasons) Salem: 1955-65, 1977-89, (shared with Keizer) 1997- (45 seasons)
Eugene is the most-tenured city in the NWL, having fielded a team in all but five of the NWL's seasons (from 1969-73, they had a PCL franchise).
Hall of Fame alumni
Eight alumni of the Northwest League are enshrined in the
Baseball Hall of Fame:
Sandy Alomar, Jr. - Spokane Indians, 1984
Garret Anderson - Boise Hawks, 1990
Kevin Appier - Eugene Emeralds, 1987
Pedro Astacio - Yakima Bears, 1990
Garrett Atkins - Portland Rockies, 2000
Jim Bouton - Portland Mavericks, 1973 & 1977
Jason Bartlett - Eugene Emeralds, 2001
Glenn Beckert - Wenatchee Chiefs, 1963
Dante Bichette - Salem Angels, 1984
Carlos Beltrán - Spokane Indians, 1996
Dallas Braden - Vancouver Canadians, 2004
Kris Bryant - Boise Hawks, 2013
Bert Campaneris - Lewiston Broncs, 1963
Tom Candiotti - Victoria Mussels, 1979
José Canseco - Medford A's, 1983
Rico Carty - Yakima Valley Braves, 1962
Ron Cey - Tri-City Atoms, 1968
Aaron Cook - Portland Rockies, 1998
Ron Coomer - Medford A's, 1987
Chris Davis - Spokane Indians, 2006
Eric Davis - Eugene Emeralds, 1980-81
Mark DeRosa - Eugene Emeralds, 1996
Dick Dietz - Eugene Emeralds, 1962
Josh Donaldson - Boise Hawks, 2007
Dave Duncan - Lewiston Broncs, 1965
Andre Ethier - Vancouver Canadians, 2003
Todd Field - Portland Mavericks batboy, 1976-77
Chone Figgins - Portland Rockies, 1998
Chuck Finley - Salem Angels, 1985
George Foster - Medford Giants, 1968
Matt Franco - Portland Mavericks batboy, 1977
Julio Franco - Central Oregon Phillies, 1979
Tom Gordon - Eugene Emeralds, 1987
Jason Giambi - Southern Oregon A's, 1992
Carlos González - Yakima Bears, 2004
Khalil Greene - Eugene Emeralds, 2002
Pedro Guerrero - Bellingham Dodgers, 1974
Bob Hamelin - Eugene Emeralds, 1988
Dave Henderson - Bellingham Mariners, 1977 Félix Hernández - Everett AquaSox, 2003
Ken Hubbs- Wenatchee Chiefs, 1961
Ender Inciarte - Yakima Bears, 2010
Ian Kinsler -- Spokane Indians, 2003
John Kruk - Walla Walla Padres, 1981
Paul Konerko - Yakima Bears, 1994
Adam Jones - Everett AquaSox, 2003
John Lackey - Boise Hawks, 1999
Mark Langston - Bellingham Mariners, 1981
Ted Lilly - Yakima Bears, 1996
Tim Lincecum - Salem-Keizer Volcanoes, 2006
Kirk McCaskill - Salem Angels, 1982
Denis Menke - Yakima Valley Braves, 1960
Wade Miley - Yakima Bears, 1996
Rick Monday - Lewiston Broncos, 1965
Bill Murray - Grays Harbor Loggers, 1978
Joe Nathan - Bellingham Giants, 1995; Salem-Keizer Volcanoes, 1997
Claude Osteen - Wenatchee Chiefs, 1958
Troy Percival - Boise Hawks, 1991
Eduardo Pérez - Boise Hawks, 1991
Juan Pierre - Portland Rockies, 1998
Kevin Pillar - Vancouver Canadians, 2011
Buster Posey - Salem-Keizer Volcanoes, 2008
Mark Reynolds - Yakima Bears, 2004
Francisco Rodríguez - Boise Hawks, 1999
Kurt Russell - Bend Rainbows, Walla Walla Islanders, Portland Mavericks, 1971-73, 1977
Tim Salmon - Bend Bucks, 1989
Jeff Samardzija - Boise Hawks, 2006
Casey Sander - Seattle Rainiers, 1975
Pablo Sandoval - Salem-Keizer Volcanoes, 2005
Kyle Schwarber - Boise Hawks, 2014
Mike Scioscia - Bellingham Dodgers, 1976
Braden Shipley - Hillsboro Hops, 2014
Ted Sizemore - Tri-City Atoms, 1966
Marcus Stroman - Vancouver Canadians, 2012
Kurt Suzuki - Vancouver Canadians, 2004
Noah Syndergaard - Vancouver Canadians, 2011
Dansby Swanson - Hillsboro Hops, 2015
Mike Sweeney - Eugene Emeralds, 1992-93
Nick Swisher - Vancouver Canadians, 2002
Kevin Tapani - Medford A's, 1986
Miguel Tejada - Southern Oregon A's, 1995
Tom Treblehorn - Bend Rainbows, 1970
Trea Turner - Eugene Emeralds, 2014
Dan Uggla - Yakima Bears, 2001
Max Venable - Bellingham Dodgers, 1976
Shane Victorino - Yakima Bears, 2000
Omar Vizquel - Bellingham Mariners, 1985
Matt Williams - Everett Giants, 1986
Mitch Williams - Walla Walla Padres, 1982
Russell Wilson - Tri-City Dust Devils, 2010
Mike Zunino - Everett AquaSox, 2012
Missildine, Harry (April 20, 1972). "Northwest League goes back to 1890". Spokesman-Review. Spokane, Washington. p. 22.
"Spokane gets berth in new ball league". Spokane Daily Chronicle. Washington. November 8, 1954. p. 18.
"Indians "on first" in baseball plans". Spokesman-Review. Spokane, Washington. November 9, 1954. p. 14.
"Northwest loop begins to shape into a tight seven-team battle". Spokane Daily Chronicle. Washington. June 11, 1955. p. 8.
Rodman, Bob (June 17, 1981). "29 years of minor league baseball". Eugene Register-Guard. Oregon. p. 1E.
"Northwest League assured for 1966". Eugene Register-Guard. Oregon. November 30, 1965. p. 3B.
Harvey, Paul, III (June 23, 1966). "4-team NWL slates 12th opener Friday". Eugene Register-Guard. Oregon. p. 2D.
"Northwest League: final standings". Eugene Register-Guard. Oregon. September 6, 1966. p. 3B.
"NW League selects Bend". The Bulletin. (Bend, Oregon). UPI. January 12, 1970. p. 8.
"Oregon dominates league". Spokesman-Review. (Spokane, Washington). Associated Press. January 13, 1970. p. 11.
"A Message From Pat O'Conner". Minor League Baseball. March 13, 2020 . Retrieved 2020.
"2020 Minor League Baseball Season Shelved". Minor League Baseball. June 30, 2020 . Retrieved 2020.
^ a b
"Northwest League Attendance". Northwest League . Retrieved 2017.
^ a b
"Northwest League Past Champions". Northwest League. Minor League Baseball . Retrieved 2017.