On Thursday, the U.S. government sold the Federal Helium Reserve, a massive underground stockpile based in Amarillo, Texas, that supplies up to 30% of the country’s helium. Once the deal is finalized, the buyer — which will likely be the highest bidder, the industrial gas company Messer — will claim some 425 miles of pipelines spanning Texas, Kansas and Oklahoma, plus about 1 billion cubic feet of the only element on Earth cold enough to make an MRI machine work. Regulatory and logistical issues with the facility threaten a temporary shutdown as it passes from public to private ownership, and...