Yes. Effective November 6, 2012, Washington state recognizes out-of-state same-sex marriages and civil unions as legal marriages.
Yes, same-sex marriages legally performed in California are recognized in Washington DC.
Yes, same-sex marriages legally performed in California are recognized in Iowa.
Yes, same-sex marriages legally performed in California are recognized in Vermont.
Yes, same-sex marriages legally performed in Massachusetts are recognized in Washington, DC.
Yes, same-sex marriages legally performed in Vermont are recognized in Washington, DC.
Yes, same-sex marriages legally performed in California are recognized in New York.
Yes, same-sex marriages legally performed in New Hampshire are recognized in Washington, DC.
Effective November 6, 2012, Washington state recognizes out-of-state same-sex marriages and civil unions as legal marriages.
Yes, inasmuch as all New Hampshire civil unions existing on January 1, 2011 were converted to marriages and Washington DC recognizes marriages performed in New Hampshire, including same-sex marriages.
No. Although the United States does generally recognize marriages performed in Mexico, the federal government does not currently recognize same-sex marriages regardless of where they were performed. However, individual states that have legalized same-sex marriage do recognize same-sex marriages performed in Mexico. Also, same-sex marriages performed in the United States are recognized by the Mexican government, including for immigration purposes.
Both California and Mexico recognize marriages performed in other jurisdictions as long as the marriage was legal in the jurisdiction where it was performed. Both, however, reserve the right to reject a marriage which is "against public policy" (e.g., incestuous or polygamous marriages). Although the State of California recognizes same-sex marriages performed anywhere it was legal between June 16, 2008 and November 5, 2008, Mexico did not begin allowing same-sex couples to marry until March 4, 2010.
Yes, inasmuch as all Washington state registered domestic partnerships existing on June 30, 2014 were converted to marriages and Iowa recognizes marriages performed in Washington state, including same-sex marriages.