According to Gallup surveys conducted from June-December 2012, the percentage of U.S. adults who identify as lesbian, gay, bisexual, or transgender (LGBT) ranges from 1.7% in North Dakota to 5.1% in Hawaii and 10% in the District of Columbia. Residents in the District of Columbia were most likely to identify as LGBT (10%). Among states, the highest percentage was in Hawaii (5.1%) and the lowest in North Dakota (1.7%), but all states are within two percentage points of the nationwide average of 3.5%.
From the Gallup research:
These results are based on responses to the question, “Do you, personally, identify as lesbian, gay, bisexual, or transgender?” included in 206,186 Gallup Daily tracking interviews conducted between June 1 and Dec. 30, 2012. This is the largest single study of the distribution of the LGBT population in the U.S. on record, and the first time a study has had large enough sample sizes to provide estimates of the LGBT population by state.