Mink are funny, they travel a lot but they will be back. I have set on mink tracks under a bridge and waited two weeks before it came back and on the other hand I have set traps and caught them the next day.
As for bait I use muskrat, beaver, fish and even Bacon,

smoked bacon. A friend and I went over to Eastern Washington in November to trap rats and found a couple of nice places with mink sign so all we had was some smoke bacon so we set two traps with the bacon came back the next day and had a nice big buck mink in one of the traps.
If you think there is a mink in the area stay there it will be back.
JC