By Air:
Dulles International Airport (IAD) is the closest airport, only 5 miles from the USGS headquarters in Reston, VA.
Reagan National Airport (DCA) is roughly 25 miles from the USGS headquarters in Reston, VA, but unlike Dulles, Reagan National has a Metro (subway) stop.
Baltimore/Washington International Thurgood Marshall Airport (BWI) is roughly 55 miles from the USGS Headquarters in Reston, VA (NOT close or convenient at all). There is a train that departs from BWI to Union Station in Washington DC, which is a Metro stop.
By Train and/or Bus:
Union Station in Washington DC is an Amtrak hub, which can be accessed by several major East Coast cities, and it is a Metro station as well.
The USGS is accessible via mass transit; there is a bus stop at the Survey building however the direct bus (Fairfax Connector 951) from the Metro and the local Reston Bus (Fairfax Connector RIBS 1 and 3) are only in service during rush hour. The local Reston buses (RIBS ) stop roughly a half-mile the Survey throughout the day.
USGS National Center Directions:
http://www.usgs.gov/ask/
http://www.usgs.gov/visitors/directions.html
Washington Metro Website:
http://www.wmata.com/
Reston/USGS Specific Fairfax Connector Bus Schedules:
http://www.fairfaxcounty.gov/connector/pdf/Rt_951_952web.pdf
http://www.fairfaxcounty.gov/connector/pdf/Rt_RIBS13web.pdf
Other Fairfax Connector Buses:
http://www.fairfaxcounty.gov/connector/north.htm
