Source: The Washington Post

http://www.washingtonpost.com/wp-dyn/articles/A36795-2001Mar21.html

On March 21, 2001, The Washington Post reported that "reflecting the growth of the Muslim population in Fairfax and Loudoun counties, Muslim leaders have announced plans to build a mosque near Dulles International Airport...It is being built by the All Dulles Area Muslim Society...The society serves about 1,600 Muslims in western Fairfax and eastern Loudoun." 150,000 to 250,000 Muslims are estimated to live in the Washington area.