to answer your question,will a coyote pick your entrance trail in the snow??probalbly.i was deer huntin a swamp one year,a wet year.had to wear hip boots to my stand and then put my huntin shoes on at the stand.3 hours into opening day of shotgun i had let 4 small bucks go 3 of whitch crossed my entrance trail with out having a clue to my presance.suddenly a coyote came thru,the water was up to his belly with very little vegitation sticking out of the water.when this yote hit my entrance trail he stopped like i hit him in the chest with a 30 caliber bullet,did a 180 and hauled butt out of there like a race horse.i could not believe he picked my scent in water thru rubber hip boots.he did not wind me in the stand,the wind was going from him to me and i was around 25 feet up in a tree.a coyotes nose is an amazing thing,i personaly believe it can not be fooled.its a good idea to know how to use both hand calls and elec call box.they will get accustomed to the repetivness of the call box,its good to mix it up.the best time to do it when its been super cold for about a week,add snow cover to that and its even better.full moon and i don't get along,i never have good luck hunting under a full moon day or night.