Map of the St. Louis area showing the position and track of the aircraft described in the post.

🇺🇸 N779UA - Boeing 777 222 - United Airlines UAL2720/UA2720, Washington Dulles (IAD) to Los Angeles (LAX) - 3.6 mi away @ 29475 ft, heading W at 525 mph. Spotted 3x before! [09:14:31 AM CDT] #AA8C39 #N779UA #B772 #UNITED #UAL2720 #UA2720 #ADSB #ADSBbot