Underground Stone Shelter, Hiding from the Blizzard and Cold

I live in the Midwest, USA, and there are some of those same structures here, for food storage, I think, but am not sure. One near to my house I was chased out of by a neighbor telling me it was unstable and not safe to be inside, lol. There are many on the Eastern side of the USA, no one knows for sure who built them or why.