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

🇺🇸 N87531 - Boeing 737NG 824/W - United Airlines UAL1651/UA1651 (SAV-ORD-DEN) - 5.0 mi away @ 37700 ft, heading NNE at 614 mph. Spotted 13x before. [05:53:52 PM CST] #AC0BC4 #N87531 #B738 #UNITED #UAL1651 #UA1651 #ADSB #ADSBbot