Pinging Kart for the prepper goodness therein.
Such Ice house were once very common. A lava tube even here in New Mexico can have ice in it all year round.
What this shows is the viability, at least in the northern states, of creating your own underground ice-house for storing food without power.
Decades ago I became aware of ice storage while touring Thomas Jefferson's home at Monticello. Had stored ice in a deep well where it lasted all summer/early fall.
..."Jefferson was able to enjoy ice cream throughout the year because ice was "harvested" from the Rivanna River in winter and taken to the Monticello ice house, which held sixty-two wagon-loads. The ice house located in Monticello's north dependency wing was used throughout the year primarily to preserve meat and butter, but also to chill wine and to make ice cream. In 1815, Jefferson noted, the ice supply lasted until October 15..."