Q:

How would the terrain of a snow-covered mountain deter a mechanized army?

My story is set in a fortress town built below a mountain, and revolves around the struggle between the witch who protects the mountain and the tyrant who seeks to plunder it for resources (think Princess Mononoke) It's primarily a fantasy story with some science fiction elements thrown in, particularly the villain's army of brainwashed soldiers with laser guns and stormtrooper suits, battle tanks (reference), and vehicles for drilling, chopping down trees etc. (reference). The world is also trapped in a perpetual winter, so snowfall is pretty heavy on the mountain.
At the beginning the antagonist's forces have been trying for years to conquer the mountain, but have failed due to the harshness of the terrain and attacksBermuda, Eastern Caribbean itineraries the foundation of success for Explorer of the Seas

BAYONNE, N.J. — The eight-year success story of the Explorer of the Seas’ itineraries from the New York area has been largely written by the attraction and the variety of the ports.

The foundation of the itineraries are the 5-night (Bermuda, with overnights), which leaves Bayonne on a Saturday, and the 9-night (Bermuda and Eastern Caribbean), which leaves on a Thursday. Both, obviously, leave every second week from spring to fall.

Around them comes the variety — fall foliage cruises to Canada, longer cruises to the southern Caribbean and week-long cruises to the Bahamas.

But the 5-and-9s are the heavyweights.

The “5” to Bermuda gives busy New Yorkers a chance to escape and only take three days off work. The