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

🇺🇸 N621UX - Embraer EMB-175 LL - United Express SKW5507/OO5507, Piedmont Triad (GSO) to Denver (DEN) - 3.6 mi away @ 30625 ft, heading W at 448 mph. Spotted 13x before! [09:06:09 AM CST] #A81BCC #N621UX #E75L #SKYWEST #SKW5507 #OO5507 #autopilot #ADSB #ADSBbot