AA 6446 then AA 6355 at Phoenix
Boise → Phoenix → St George
Timetable, Phoenix time
07:55AA 6446 from Boise at the gate
20:00AA 6355 to St George leaves the gate
12 h 05 apart on the timetable
AA 6355 leaves 12 h 05 after AA 6446 arrives on the timetable: more than half a day, so not a connection we count.