WN 209 then UA 2121 at Denver
St Louis → Denver → Grand Rapids
Timetable, Denver time
18:50WN 209 from St Louis at the gate
17:45UA 2121 to Grand Rapids leaves the gate
22 h 55 apart on the timetable, overnight
UA 2121 leaves 22 h 55 after WN 209 arrives on the timetable: more than half a day, so not a connection we count.