AA 3487 then DL 1979 at O'Hare
Missoula → Chicago → Salt Lake City
Timetable, Chicago time
18:25AA 3487 from Missoula at the gate
19:17DL 1979 to Salt Lake City leaves the gate
52 min apart on the timetable
The last days
AA 3487 and DL 1979 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.