Well for the creek I am trapping, he had better be an excellent swimmer, cause most places are wide and deep
I don't know how wide is "wide" and I don't know the velocity of the water's current but sometimes the water, itself, tells you how to trap the mink.
I'm judging this is not an insignificent creek meandering through somebody's back pasture. Are we talking "river" type creek here?
I trap a lot of bigger waters, bigger waters mean better feeding opportunities for the mink plus more cover and it all adds up to more mink.
Now for all that people are going to tell you about a mink,
he is not a particularly good swimmer. Just look at a mink's hind feet. He doesn't have those oversized webbed kickers like a muskrat or beaver.
Don't get me wrong, a mink can swim but he is no muskrat in the water.
It has long been my expirence that a creek or small river, say 30 yards or more wide, that mink don't cross from side much..... if at all. Stop your vehicle on one side of a brdige spanning such a creek or river, make your sets then cross the bridge to the other side and make sets on that side of the creek too. You are now trapping two seperate mink populations.
In deep swift water it seldon pays to make too many sets in the water. In this type of a situtation I've always found, and proven to myself beyond any doubt, that any passing mink will mostly likely stay on the high and dry. This is where dry sets can pay off.
The same somewhat holds true for roaring mountian brooks. A mink will take to water in the calm eddys and pools but in the flowing sections the mink will be traveling the banks.
Your number 1 longsprings are just fine for mink. Not perfect but ok. In years past I have taken untold numbers of mink in #1s.
Where you are trapping I would look for crumbling overhang banks, trees growing out of the side of the creek banks with the roots exposed and the ever deadly highwater muskrat den. At all of these locations a dry twig dipped into a bottle of a good mink lure can help attract the mink to your sets. Bait will work too but it will also attract other species such as raccoons and opposums.