You most likely did.
You probably saw UA5678 takeoff indeed, as Petazulu said, for ASE. San Francisco has also been receiving a daily SFO
-ASE flight with the BAe146, of which that will end in the beginning of April.
The BAe146's are operated by United Express/Air Wisconsin. In LAX
they are ground-handled by SkyWest (both CS
& Ramp), and in SFO
they are ramped by SkyWest, but CS
is done by United.
Head in the clouds... yet feet planted firmly on the ground.