Marty too. I think there are smells. I know he sticks his head in like deer tracks and then stares off in the distance like "oh there it is". And you know how some dogs on a walk will sniif and go on? Riley our previous pup, would stand there for hours at the same spot if we allowed it.
There was actually nothing under the snow - I checked to be sure. At times I think he's training to be an avalanche dog. Jackson will intentionally bury a toy in the deepest snow then dig for it and bring it to me.
Penny does the exact same thing. I always think maybe her nose got too hot.
We got her in February and there was a lot of snow. She'd dive her face into the snow and then push with her little hind legs, propelling herself down the hill with her little fuzzy butt above the snow. I'd never seen anything like that. She's had us smiling from day 1.