solveg

I know the answer to that... It primarily occurs in hot weather. You often wear skimpy clothes with few pockets, and the poop heats up and really, really stinks in that hot bag. If there aren't any garbage bins anywhere near, then you lay it by the trail so you pick it up on your return. This is especially true if the dog poops right in the beginning of the hike, and the only garbage receptacles are at the mouth of the trail. You don't want to carry that stuff for 3-4 hours, even in a back pack.

99% of the time you find your poop on the way back, 1% of the time you miss it or can't remember where you put it, but another dog owner will spot it, know what's going on, and grab it up if they're close to the trail mouth.

The thing to watch out for is that if there's not garbage bin at the mouth, people have to tie the baggies to their cars, because after 4 hours in the heat, your car will become a jar of poop perfume if you bring it in. Usually there's a garbage bin at the main gate of the state park, at the very minimum. But if that's far enough away, a forgetful dog owner might drive all the way home with a baggie of poop tied to the rack of her green subaru, putting everyone behind her at risk in case of bag failure!!!!!!