UA 214 then UA 543 at San Francisco
St Louis → San Francisco → Las Vegas
Timetable, San Francisco time
21:41UA 214 from St Louis at the gatealso OZ 6344, NZ 9701
14:20UA 543 to Las Vegas leaves the gatealso AC 3886, NH 7308, CA 7316, NZ 9222
16 h 39 apart on the timetable, overnight
UA 543 leaves 16 h 39 after UA 214 arrives on the timetable: more than half a day, so not a connection we count.