AA 1878 then 1I 604 at Salt Lake City
Dallas-Fort Worth → Salt Lake City → Las Vegas
Timetable, Salt Lake City time
10:30AA 1878 from Dallas-Fort Worth at the gate
17:001I 604 to Las Vegas leaves the gate
6 h 30 apart on the timetable
The last days
AA 1878 and 1I 604 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.