I know that Skywest flies for United Express, Delta Connection, and Continental Connection. So my question is, when a pilot gets hired, do they get to pick which express airline they want to fly for or can they fly for every one? I.E. just fly United or Delta routes or could a pilot take-off on a United flight, land in LAX then jump to Delta and head to SLC? I know it sounds stupid but i've always wondered this.

Thank you in advance!

Taylor