WN 856 then WN 1277 at Denver
Dallas → Denver → Salt Lake City
Timetable, Denver time
08:45WN 856 from Dallas at the gate
19:35WN 1277 to Salt Lake City leaves the gate
10 h 50 apart on the timetable
The last days
WN 856 and WN 1277 weren’t both flown 15 min to 12 h apart in the last 21 days.
Statistics from past flights, not live flight information. Always check times and your connection with your airline, and don’t base travel or booking decisions on these numbers.