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

🇺🇸 N577DN - Airbus A321 271NXSL - Delta Air Lines DAL361/DL361 (DTW-SFO-DTW) - 4.2 mi away @ 36175 ft, heading W at 510 mph. Spotted 2x before! [08:41:36 AM CDT] #A768C2 #N577DN #A21N #DELTA #DAL361 #DL361 #ADSB #ADSBbot