Wilayah Barat (MLS)
Formasi tim

| 2017 |
| --- | --- | --- |

| Tim | Kota | Stadion |
| Colorado Rapids | Commerce City, CO | Dick's Sporting Goods Park |
| FC Dallas | Frisco, TX | Toyota Stadium |
| Houston Dynamo | Houston, TX | BBVA Compass Stadium |
| Los Angeles Galaxy | Carson, CA | StubHub Center |
| Minnesota United FC | Minneapolis, MN | TCF Bank Stadium |
| Portland Timbers | Portland, OR | Providence Park |
| Real Salt Lake | Sandy, UT | Rio Tinto Stadium |
| San Jose Earthquakes | San Jose, CA | Avaya Stadium |
| Seattle Sounders FC | Seattle, WA | CenturyLink Field |
| Sporting Kansas City | Kansas City, KS | Children's Mercy Park |
| Vancouver Whitecaps FC | Vancouver, BC | BC Place |

Perubahan:  Minnesota United FC ditambahkan pada 2017 sebagai bagian dari pengembangan MLS.
| 2015–16 |
| --- | --- | --- |

| Tim | Kota | Stadion |
| Colorado Rapids | Commerce City, CO | Dick's Sporting Goods Park |
| FC Dallas | Frisco, TX | Toyota Stadium |
| Houston Dynamo | Houston, TX | BBVA Compass Stadium |
| LA Galaxy | Carson, CA | StubHub Center |
| Portland Timbers | Portland, OR | Providence Park |
| Real Salt Lake | Sandy, UT | Rio Tinto Stadium |
| San Jose Earthquakes | San Jose, CA | Avaya Stadium |
| Seattle Sounders FC | Seattle, WA | CenturyLink Field |
| Sporting Kansas City | Kansas City, KS | Children's Mercy Park |
| Vancouver Whitecaps FC | Vancouver, BC | BC Place |

Perubahan:  Chivas USA dibubarkan.  Sporting Kansas City dan Houston Dynamo pindah dari Wilayah Timur ke Wilayah Barat.
| 2011–14 |
| --- | --- | --- |

| Tim | Kota | Stadion |
| Chivas USA | Carson, CA | StubHub Center |
| Colorado Rapids | Commerce City, CO | Dick's Sporting Goods Park |
| FC Dallas | Frisco, TX | Toyota Stadium |
| LA Galaxy | Carson, CA | StubHub Center |
| Portland Timbers | Portland, OR | Providence Park |
| Real Salt Lake | Sandy, UT | Rio Tinto Stadium |
| San Jose Earthquakes | Santa Clara, CA | Stadion Buck Shaw |
| Seattle Sounders FC | Seattle, WA | CenturyLink Field |
| Vancouver Whitecaps FC | Vancouver, BC | BC Place |

Perubahan:  Portland Timbers dan Vancouver Whitecaps FC bergabung pada tahun 2011 sebagai bagian dari pengembangan liga.  Houston pindah ke Wilayah Timur.
| 2009–10 |
| --- | --- | --- |

| Tim | Kota | Stadion |
| Chivas USA | Carson, CA | StubHub Center |
| Colorado Rapids | Commerce City, CO | Dick's Sporting Goods Park |
| FC Dallas | Frisco, TX | Toyota Stadium |
| Houston Dynamo | Houston, TX | Robertson Stadium |
| LA Galaxy | Carson, CA | StubHub Center |
| Real Salt Lake | Sandy, UT | Rio Tinto Stadium |
| San Jose Earthquakes | Santa Clara, CA | Stadion Buck Shaw |
| Seattle Sounders FC | Seattle, WA | CenturyLink Field |

Perubahan:  Seattle Sounders FC bergabung pada tahun 2009, sebagai bagian dari pengembangan MLS.
| 2008 |
| --- | --- | --- |

| Tim | Kota | Stadion |
| Chivas USA | Carson, CA | StubHub Center |
| Colorado Rapids | Commerce City, CO | Dick's Sporting Goods Park |
| FC Dallas | Frisco, TX | Toyota Stadium |
| Houston Dynamo | Houston, TX | Robertson Stadium |
| LA Galaxy | Carson, CA | StubHub Center |
| Real Salt Lake | Salt Lake City, UT | Rice-Eccles Stadium |
| San Jose Earthquakes | Santa Clara, CA | Stadion Buck Shaw |

Perubahan:  San Jose Earthquakes kembali aktif mengikuti liga mulai musim 2008
| 2006–07 |
| --- | --- | --- |

| Tim | Kota | Stadion |
| Chivas USA | Carson, CA | StubHub Center |
| Colorado Rapids | Commerce City, CO | Invesco Field at Mile High (2006)   Dick's Sporting Goods Park (2007) |
| FC Dallas | Frisco, TX | Toyota Stadium |
| Houston Dynamo | Houston, TX | Robertson Stadium |
| LA Galaxy | Carson, CA | StubHub Center |
| Real Salt Lake | Salt Lake City, UT | Rice-Eccles Stadium |

Perubahan:  San Jose Earthquakes tidak aktif.  Houston Dynamo bergabung dengan liga pada musim 2006 sebagai tim baru.
| 2005 |
| --- | --- | --- |

| Tim | Kota | Stadion |
| Chivas USA | Carson, CA | StubHub Center |
| Colorado Rapids | Denver, CO | Invesco Field at Mile High |
| FC Dallas | Frisco, TX | Stadion Cotton Bowl   Toyota Stadium |
| LA Galaxy | Carson, CA | StubHub Center |
| Real Salt Lake | Salt Lake City, UT | Rice-Eccles Stadium |
| San Jose Earthquakes | San Jose, CA | Spartan Stadium |

Perubahan:  Chivas USA dan Real Salt Lake bergabung pada tahun 2005, sebagai bagian dari pengembangan MLS.  Kansas City Wizards pindah ke Wilayah Timur  Dallas mengubah nama mereka dari Dallas Burn ke FC Dallas
| 2002–04 |
| --- | --- | --- |

| Tim | Kota | Stadion |
| Colorado Rapids | Denver, CO | Invesco Field at Mile High |
| Dallas Burn | Dallas, TX | Stadion Cotton Bowl   Dragon Stadium (2003) |
| Kansas City Wizards | Kansas City, MO | Stadion Arrowhead |
| LA Galaxy | Carson, CA | Rose Bowl (2002)   StubHub Center |
| San Jose Earthquakes | San Jose, CA | Spartan Stadium |

Perubahan tahun 2001:  Divisi Barat kembali menjadi Wilayah Barat, karena adanya pemberhentian kontrak Miami Fusion dan Tampa Bay Mutiny, yang menyebabkan dibekukannya Divisi Tengah  Dallas Burn pindahan dari Divisi Tengah
| 2000–01 |
| --- | --- | --- |

| Tim | Kota | Stadion |
| Colorado Rapids | Denver, CO | Mile High Stadium |
| Kansas City Wizards | Kansas City, MO | Stadion Arrowhead |
| LA Galaxy | Pasadena, CA | Rose Bowl |
| San Jose Earthquakes | San Jose, CA | Spartan Stadium |

Perubahan tahun 1999:  Wilayah Barat berubah namanya menjadi Divisi Barat, sehubungan dengan dibentuknya Divisi Tengah.  Chicago Fire dan Dallas Burn pindah ke Divisi Tengah.  San Jose mengubah nama mereka dari Clash menjadi Earthquakes
| 1998–99 |
| --- | --- | --- |

| Tim | Kota | Stadion |
| Chicago Fire | Chicago, IL | Soldier Field |
| Colorado Rapids | Denver, CO | Mile High Stadium |
| Dallas Burn | Dallas, TX | Stadion Cotton Bowl |
| Kansas City Wizards | Kansas City, MO | Stadion Arrowhead |
| LA Galaxy | Pasadena, CA | Rose Bowl |
| San Jose Clash | San Jose, CA | Spartan Stadium |

Perubahan tahun 1997:  Chicago Fire bergabung pada tahun 1998 sebagai bagian dari pengembangan MLS.
| 1997 |
| --- | --- | --- |

| Tim | Kota | Stadion |
| Colorado Rapids | Denver, CO | Mile High Stadium |
| Dallas Burn | Dallas, TX | Stadion Cotton Bowl |
| Kansas City Wizards | Kansas City, MO | Stadion Arrowhead |
| LA Galaxy | Pasadena, CA | Rose Bowl |
| San Jose Clash | San Jose, CA | Spartan Stadium |

Perubahan tahun 1996:  Kansas City mengubah nama mereka dari Wiz menjadi Wizards
| 1996 |
| --- | --- | --- |

| Tim | Kota | Stadion |
| Colorado Rapids | Denver, CO | Mile High Stadium |
| Dallas Burn | Dallas, TX | Cotton Bowl |
| Kansas City Wiz | Kansas City, MO | Stadion Arrowhead |
| LA Galaxy | Pasadena, CA | Rose Bowl |
| San Jose Clash | San Jose, CA | Spartan Stadium |

Perubahan tahun 1995:  Pembentukan Major League Soccer