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

🇺🇸 N8810L - Boeing 737MAX 8 - Southwest Airlines SWA4249/WN4249, Phoenix Sky Harbor (PHX) to Chicago Midway (MDW) - 4.3 mi away @ 37975 ft, heading ENE at 529 mph. Spotted 57x before! [05:30:21 PM CDT] #AC23EF #N8810L #B38M #SOUTHWEST #SWA4249 #WN4249 #ADSB #ADSBbot