WN 757 then UA 645 at Denver
Cleveland → Denver → Sioux Falls
Timetable, Denver time
18:45WN 757 from Cleveland at the gate
17:25UA 645 to Sioux Falls leaves the gate
22 h 40 apart on the timetable, overnight
UA 645 leaves 22 h 40 after WN 757 arrives on the timetable: more than half a day, so not a connection we count.