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

🇺🇸 N8906K - Boeing 737MAX 8 - Southwest Airlines SWA1376/WN1376, Chicago Midway (MDW) to Austin-Bergstrom (AUS) - 4.7 mi away @ 40125 ft, heading SW at 482 mph. Spotted 28x before! [08:18:27 PM CST] #AC4888 #N8906K #B38M #SOUTHWEST #SWA1376 #WN1376 #ADSB #ADSBbot