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

🇺🇸 N77871 - Boeing 757 33N/W - United Airlines UAL1702/UA1702 (IAD-SFO-DEN) - 4.1 mi away @ 34000 ft, heading W at 564 mph. Spotted 6x before! [09:55:01 AM CDT] #AA8A26 #N77871 #B753 #UNITED #UAL1702 #UA1702 #ADSB #ADSBbot