If you are second district in Washington like me, it's here: http://www.house.gov/larsen/
Out of staters? Every complaint helps. Contact your Congress folk to remind them that when one group is discriminated against, it diminishes everyone. Most congressfolk have staffers who log yes/no on contacts about various topics and numbers really help tip scales one way or the other.
Here is a petition as well: http://www.ipetitions.com/petition/transgender_inclusive_ENDA/?e