The Helium Spectrum
The bright yellow line in the helium spectrum is what astronomers in 1868 noticed when viewing the suns prominences during a total eclipse in India.

There is simply no element like it. From its history to its modern uses, helium is a fascinating element that is quickly disappearing. Although it is the second most abundant gas in the universe (behind hydrogen), it is considered a rare gas on earth. All helium which is used today is extracted from natural gas streams where concentrations are high enough to economically separate.

Currently, the United States is the largest producer of helium in the world.  Although new helium extraction / purification plants are on-line in other countries, they are not able to meet their own demand and rely on U.S. imports.  Last year (2010), the United States exported an estimated 2.50 billion cubic feet (BCF) of helium to Europe and Asia.  Interestingly, this helium stored in Cliffside field belongs to U.S. taxpayers and it is being sold at a tremendous discount to true value.  This is one of the problems that was addressed by the National Research Council's, Selling the Nation's Helium Reserve. (this publication can be downloaded free with registration)

As the United States’ Cliffside helium storage facility is dwindling, no new helium production has been brought online.  Industrial gas companies have continuously raised retail helium prices as a result. 

For more information on the United States helium industry, please go to the following links:

Helium Statistics and Information (United States Geological Survey "USGS")
The Impact of Selling the Federal Helium Reserve (National Academies Press - 2000)

For information on the United States’ Cliffside field, please read Helium Storage in Cliffside Field by Miles D. Tade.  Published in the Journal of Petroleum Technology, July 1967.