for the most part as they were not mixed with cement I assume. The Pops chips were and the ones I have seen and dug have concrete residue on them. That may explain why there are not many out there? Also...it seems like a whole slew of people jumped in to get those PB chips as they were just sitting there.You have to work for these Pops chips and I don't know how many people actually went out to poke around. Also....the people who went out to the Nevada Landing site are mainly collectors whereas the PB people just wanted to make a fast buck. Who knows?