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

🇺🇸 N68880 - Boeing 737NG 924ER/W - United Airlines UAL2171/UA2171, Charlotte/Douglas (CLT) to Denver (DEN) - 4.4 mi away @ 35350 ft, heading WNW at 508 mph. Spotted 8x before! [06:00:46 PM CDT] #A92478 #N68880 #B739 #UNITED #UAL2171 #UA2171 #ADSB #ADSBbot