http://thehiddenwoodsmen.com/the-french-trade-bag/
The french trade bag from "The Hidden Woodsmen". It's not a backpack, but I didn't really need all that much. But if you want a backpack, check out the Classic Ruck at the web site above.
It's worked out perfect for all my loose tackle, small tackle boxes, gear, water, etc for both shore fishing and on the water fishing. It's also a great EDC bag. If you need more, Malcolm also has Haversacks, Hunting Packs, Day Rucks and other gear that might suit your needs. Great looking gear, durable materials and very well put together stuff.
As an added bonus, it's 100% American made by a small business, artisan, craftsman.