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

🇺🇸 N203NN - Embraer EMB-175 LR - American Eagle ENY4186/MQ4186 (ORD-SAT-ORD) - 4.8 mi away @ 34525 ft, heading SW at 486 mph. Spotted 28x before. [03:36:45 PM CDT] #A19E61 #N203NN #E75L #ENVOY #ENY4186 #MQ4186 #autopilot #ADSB #ADSBbot