A few items I always pack with me are a role of electrical tape. Keep that muzzle covered. Bulged barrels are a real possibility in northern Canada. A Bic lighter in case you have to make a fire. Matches, strikers and Zippos are useless once submerged but not a Bic lighter. Rubber bottomed, leather topped boots for wet snow such as those made by Lacrosse. Your all leather boots will give up in a matter of 2 hours in wet snow. Remember the Battle of the Bulge. It was cold wet feet that crippled or led to the deaths of so many brave men.Make sure you binos and scopes have lens covers that keep the lenses dry. Baby wipes and premium toilet paper are useful items that should not be overlooked.
GPS units are great but a 30 dollar compass does not need batteries. Make sure it has a lanyard and wear it around your neck. The toque you will be wearing should be made of wool with a thinsulate liner. Wind and water will not go through these.
