DL 3901 then DL 4279 at Salt Lake City
Helena → Salt Lake City → St George
Timetable, Salt Lake City time
08:38DL 3901 from Helena at the gate
20:45DL 4279 to St George leaves the gate
12 h 07 apart on the timetable
DL 4279 leaves 12 h 07 after DL 3901 arrives on the timetable: more than half a day, so not a connection we count.