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

🇳🇱 PH-BQK - Boeing 777 206ER - KLM Royal Dutch Airlines KLM661/KL661, Amsterdam Schiphol (AMS) to George Bush Intcntl/Houston (IAH) - 4.4 mi away @ 37950 ft, heading SSW at 570 mph. Spotted once before! [11:40:56 AM CDT] #484371 #PH_BQK #B772 #KLM #KLM661 #KL661 #ADSB #ADSBbot