You can vacation out of the last leg of a pairing at Skywest. You can't straight drop it, but you can use vacation/user time to drop it. When I was on reserve in FAT at a time when we were overstaffed almost all I ever got called for was to deadhead to SFO or LAX and fly one leg back to FAT because everyone would vacation out of the last leg to commute. I used to call them one leg wonders.

Now that we're understaffed in most domiciles getting something like that approved is probably rare, but it's still possible to request it.