This is what I keep on my sled for short trips.
-spare belt
-spare plugs for the 2-strokes
-extra quart of 2-stroke oil for the 2-strokes
-stock tool kit
-spare key for the sled
-a quick fix first aid kit (band-aids, tums, ibuprofen, Kleenex, wet wipes....) what ever you always grab when you're home
-I have a major bleed kit (tourniquet, gauze, Israeli bandage, tape, first aid shears, and a space blanket) Hopefully I'll never have to use this
-tow strap for snowmobiles
-maps
-compass
-lighter
-beanie or hat for the stops
-drink and snacks
On me I usually have:
-phone
-knife or multi-tool
-lighter
-wallet
-cigars
We usually don't ride hard and long, so drink, snacks and cigars are nice on our breaks.
At the truck:
-more spare belts
-more 2-stroke oil
-spare parts
-more extensive tool kit
-roll-up deer sled for the really bad recoveries
-extra riding gear
-extra gas