Originally Posted by
jsloan
UA does not have a nonstop IAH-YQU.

But generally the most profitable place to try splitting one UA trip into two search results is between two UA-operated flights. My guess is that OP is flying VCT-IAH-YYC-YQU -- UA does operate IAH-YYC.
A connection in YYC is my assumption too. I would have understood, though still be surprised by a IAH-YMM flight.