DL 3901 then WN 2258 at Salt Lake City
Helena → Salt Lake City → Las Vegas
Timetable, Salt Lake City time
08:38DL 3901 from Helena at the gate
21:25WN 2258 to Las Vegas leaves the gate
12 h 47 apart on the timetable
WN 2258 leaves 12 h 47 after DL 3901 arrives on the timetable: more than half a day, so not a connection we count.