The following was compiled by Argitxu Camus Etchecopar.

Founding members of NABO (1973):
Reno Zazpiak Bat Club (founded in 1967)
Boise Euzkaldunak (founded in 1949)
Elko Euzkaldunak Club (founded in 1959)
San Francisco Basque Club (founded in 1960)
Ely (founded in 1960), inactive
Kern County Basque Club, Bakersfield (founded in 1944)
Grand Junction Colorado, Western Slopes Association, (1960s/inactive)
Ontario, OR Basque Club (founded in 1947)

Joined 1977:
Winnemucca, Euskaldunak Danak Bat (founded in 1954)
La Puente Handball Court, associate member (founded in 1947)
Los Angeles Oberena, associate member founded in the 1980s)
Menlo Park Zazpiak Bat Club (founded in 1964), inactive

Joined 1978:
Chino Basque Club (founded in 1967)
Los Banos Basque Club (founded in 1964)

Joined 1979:
Fresno Basque Club (founded in 1978)
Caldwell Euzkaldunak charities, associate member (founded in 1970) inactive
Southern California Eskualdun Club (founded in 1946)
Salt Lake City, Basque Club of Utah (founded in 1973)

Joined 1982:
San Francisco Basque Cultural Center (founded in 1979)
Buffalo Wyoming, Big Horn Basque Club (founded in 1981)

Joined 1984:
Oinkari Basque Dancers, Boise (founded in 1960)

Joined 1985:
Las Vegas Lagun Onak (founded in 1983) 

Joined 1986:
Euskal Herria Basque Club of Washington D.C, (founded in 1981), inactive

Joined 1987:
Gardnerville, Mendiko Euskaldun Cluba (founded in 1981)
Gooding Basque Club (founded in 1982) 

Joined 1990:
Boise Basque Museum and Cultural Center (founded in 1985)

Joined 1991:
Anaitasuna, San Francisco (founded in 1991)
Rocksprings, Alkartasuna Southwestern Wyoming Basque Club (founded in 1989)

Joined 1992:
Susanville Basque Club (founded in 1975)

Joined 1993:
Euzko-Etxea of New York (founded in 1913)
Ventura Basque Club, Itxaso Alde (founded in 1993)

Joined 1994:
Washington State Basque Club, inactive
Portland Basque Club (founded in 1992), inactive since 2001

Joined 1995:
Society of Basque Studies in America (founded in 1979)

Joined 1996:
Marin Sonoma (founded in 1989).

Joined 1997:
Spokane Inland Northwest Basque Club (founded in 1997), inactive since 2001
Euskal Lagunak Mountain Home Basque Association (founded in 1960)

Joined 1999:
Battle Mountain Basque Club (founded in 1997)
Seattle Euskal Etxea (founded in 1997).

Joined 2001:
Center for Basque Studies, Reno (founded in 1967) 

Joined 2002:
Homedale Txoko Ona Basque Club (founded in 2000)

Joined 2003:
San Francisco, Basque Educational Organization (founded in 1984) 

Joined 2004:
Colorado Euskal Etxea (founded in 2003) 

Joined 2005:
Cenarrussa Center for Basque Studies (founded in 2003)

Joined 2006:
Iparreko Ibarra (founded in 2005)

Joined 2007:
Santa Rosa Basque Club (Paradise Valley, NV; founded 2006)
Washington D.C. Euskal Etxea (founded 2007)