Not too many good thrift stores around me that carry outdoor gear, but have some good army surplus stuff.
Newest pickup was this fleece pant, reinforced at knees and seat with zips and waist cinches up. $6 CAD. Some guy prob died in them, but whatever.
And this 'gas mask bag', seems like waxed canvas with some sort of strap that came with it. $3 CAD, velcro still in good condition. I'll prob use it to haul into the trees for my cookset/food as a bear bag. Top rolls over a few times and velcros down, a large pocket on the opposite side, and a small pocket on the bottom. Neither really bellow out, so they don't seem too useful. Seems pretty resilient to rodents getting in though.
