DL 1492 then DL 1340 at Salt Lake City
St Louis → Salt Lake City → Billings
Timetable, Salt Lake City time
21:18DL 1492 from St Louis at the gate
21:00DL 1340 to Billings leaves the gate
23 h 42 apart on the timetable, overnight
DL 1340 leaves 23 h 42 after DL 1492 arrives on the timetable: more than half a day, so not a connection we count.