Are these ballast bags for a hot air balloon? While driving around on the back side of Aspen Mountain (so up around 10,000 feet altitude) we came upon these bags of ash.  They look like they could be opened up on the bottom to let the contents out, our best guess is that they are ballast bags for a hot air balloon.  You can see my brother's legs in the first picture for some kind of scale.

Were we right?
Almost definitely not.

Hot air balloons control their height by changing their temperature, they don't typically use ballast bags. It's possible that these were ballast bags on a gas balloon, but ash seems like a strange choice for weight considering how light it is.