Any store bought bait work decent?

Beef scraps from your local butcher is dynamite marten bait.
If the local butcher also processes moose-just as good.

Game bird scraps work too. A slight taint on em doesn’t hurt either

I've done well with chicken guts.

This.
And I imagine chicken. Duck is great too, better than beaver imo.

Don’t over think it. I’ve got marten off a squirrel tail dabbed in a bit of Marten Magic.
Before a marten ever tried beaver, do you think he knew he was supposed to prefer it over burnt fur?……. lol
Fish, or any of the frozen critters in the freezer will work.

Thank you!

I have caught them on chunks of prairie dog and jack rabbit. Nelson bait home made, pigeons, I don't think they are too picky. Late winter especially.

What’s Nelson bait?

Any red flesh will do but the best is beaver, horse, woodchuck, skunk, housecat or bobcat. Cut into desired sized pieces, or grind. Place in gallon jar, 2/3 full. Place lid on loosely, just enough to keep flies out. Place in warm but shaded area until bait swells and juice forms on it and it has a frothy look to it. Just a good taint, not rotten. Stir in solution with a long fork. Mix well and when finished, the solution should cover the settled bait mass by about an inch. Bury a foot or so deep in earth trenches, lids on firm but not tight as jars may explode. Age in trench for at least one month.

Solution:

In a gallon jar, place 2 pints sun rendered fish oil (catfish or trout is best), 1 pint of glycerine and 20 heaping tablespoons of sodium benzoate. Add 1 ounce of valerian, 1 ? ounces of tincture of aseofetida, then 8 tablespoons of ground beaver castor, 20 drops of pure skunk essence, and 1 pint of pure red fox urine. Fill jug the rest of the way with pure rainwater, shake well and age at least one week prior to adding to bait formula. It helps to add 4 ounces of ground muskrat or mink glands.

Doubt they process a lot of moose in Nebraska, but they probably do a lot of deer.

Muskrat also works well, I've even caught them on half a marten carcass. Any meat will probably work to an extent, but I prefer meats with a higher fat content. Bear also works well, and I've caught them on bobcat and cougar.

Plenty of roadkill squirrels laying around!

Ya don't even need meat. I use only feathers. Heck I caught one on a chocolate chip cookie ))

I've tried blacktail deer scraps with nearly zero success.
Oldtimers (early 1900's) in the pacific northwest used lightly salted salmon. They would wrap it in a layer of of fine mesh screen to prevent birds and shrews from eating it. You still find evidence of this in old set in the Cascade mountains.
Early 1900's marten set I found a coulple years ago. Notch sets were considered the standard go-to set, often a piece of bark with a small opening for the marten was nailed over the notch to protect from snow and birds.

I caught fox in 330s a couple times but I dont use them for catching fox.

That’s pretty cool Waggler

Getting a little off the subject, but it's interesting to examine these old notch sets, the axemanship is remarkable. You can tell those folks 125 years ago really knew how to sharpen and use a long bitted northwest felling axe.