What the hell did you have in your pack to make it weigh 100lbs? When I go backpacking, 30 odd miles a day for three or four days, the heaviest I have carried was 40lbs.
That's for COLD weather, and 2-3 weeks time
Reinforced (with steel) backpack (how else am I going to carry this?)
4 full changes of clothes, weighs quite a bit
2 pairs of Snow Boots
assorted food-some canned (lots of tuna, I usually consume 3000 Calories per day in that kind of weather),
Cast Iron Girdle,
Hatchet,
Parachute cord,
rock climbing gear,
Camera with lots of batteries
Hand Warmers
Tough 4 season tent
Gallons of water,
Purification Equipment,
Shovel
The list goes on...
But this is for like 2-3 weeks in Cold weather, my backpack normally doesn't weigh anywhere near that, more like 40 pounds normally, being Minimalist probably like 25 for a couple days