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

🇺🇸 N783UA - Boeing 777 222ER - United Airlines UAL538/UA538 (EWR-SFO-MFR) - 4.7 mi away @ 40100 ft, heading W at 526 mph. Spotted 3x before! [04:00:17 PM CDT] #AA9D6E #N783UA #B772 #UNITED #UAL538 #UA538 #ADSB #ADSBbot