WTB ~ Youth sized backpacks for backpacking

[GAbearclaw]

My knuckleheads and I are going to do some backcountry trout fishing in the sierra's and I would love to get them some 3000ci or so packs without buying new since they will likely not fit very long.

Anyone got anything? Old frame pack, etc. works fine. Really just something big enough they can carry their sleeping bag and clothes, etc. for multi-night backpack trips. Boys are 11 and 13.

Thanks