UA 1883 then UA 406 at San Francisco
Houston → San Francisco → Las Vegas
Timetable, San Francisco time
07:28UA 1883 from Houston at the gatealso EK 6028, NZ 9216
21:10UA 406 to Las Vegas leaves the gatealso AC 4025, VA 8562, LH 8940, NZ 9229
13 h 42 apart on the timetable
UA 406 leaves 13 h 42 after UA 1883 arrives on the timetable: more than half a day, so not a connection we count.