I had a 60 lb backpack when I hiked Philmont years ago. I wasn't the heaviest one there, not by far.

No, a 42 kg backpack. A bit more than 88 pound. With a 10 kg one on front so 52 kg in total. I used it on a 3.5 month expedition from Vancouver via Whitehorse, then paddled the Yukon to Emmonak, then Alakanuk at the Bering Strait, back to Emmonak, then Anchorage, hitchhiked to the start of the Alaska Marine Highway at Skagway, then to Prince Rupert, from there to Vancouver Island, then back to Vancouver.

It was quite the trip. I don't really hold with the 'travel light' motto and mostly use old military gear, normal food instead of the freeze dried stuff, normal (but smallish) pots and pans, etc. On the Yukon trip I also happened to have a solar-powered water- and probably bullet-proof computer with me plus 2 10W solar panels, that was what I had in the 10kg pack on front.