The USG had/has a store the National Helium Reserve [1]. It was being sold off so I am unsure how much is still in it, but to answer your question you store it

The USG had/has a store the National Helium Reserve [1]. It was being sold off so I am unsure how much is still in it, but to answer your question you store it underground. Edit. It looks that the National Helium reserve will be sold off by 2018 [2]. 1. https://en.wikipedia.org/wiki/National_Helium_Reserve https://en.wikipedia.org/wiki/National_Helium_Reserve 2. https://en.wikipedia.org/wiki/Helium_production_in_the_United_States https://en.wikipedia.org/wiki/Helium_production_in_the_Unite...