The "Orthodoxy in America" website maintains an excellent database of Orthodox parishes in America, searchable by zipcode. Click on the Orthodoxy in America link above, and then on Church Locator. Each of the jurisdictional websites also maintains a parish directory.

Jurisdictional parish directories:

American Carpatho-Russian Orthodox Diocese of the U.S.A.

Antiochian Orthodox Christian Archdiocese

Bulgarian Orthodox Diocese of the USA

Greek Orthodox Archdiocese of America

Orthodox Church in America

Romanian Orthodox Archdiocese in the Americas

Russian Orthodox Church Outside of Russia

Serbian Orthodox (Midwestern American Metropolitanate)

Serbian Orthodox (New Gracanica Metropolitanate)

Ukrainian Orthodox Church of the USA