Molycorp Inc. is trying to figure out how to ramp up production at a competitive price, with minimal environmental harm. In 2008, the company reopened Mountain Pass, touting new technologies that eliminate the need for pipelines and reduce water use by 96 percent. Its $531 million redeveloped facility will likely be one of just two outside China that can produce rare earth oxides. The company also expects to manufacture alloys and magnets.

How other mines would deal with processing and the disposal of thorium remains a thorny problem, however, according to Jim Burnell of the Colorado Geological Survey.  Plans to ship radioactive materials -- by train or truck --would likely face tough opposition and could prove expensive. And though Mountain Pass could process metals from other mines after its plant is complete in 2013, says Molycorp spokesman Jim Sims, the facility will be fine-tuned to refine local materials and will not be able to process ores with high thorium contents.

Ranta's company might use Mountain Pass, he says, but the Bear Lodge mine's metals will likely go through initial processing in Wyoming, where the radioactive elements will be removed and stored. Other operations, all of which lag behind Mountain Pass and Bear Lodge, apparently hope the federal government will come to the rescue.

Five years ago, Ed Cowle, a New Yorker with a background in finance, and some partners bought claims along Lemhi Pass on the Idaho-Montana border, where Lewis and Clark first crossed the Continental Divide. After initially launching the business as an investment in thorium, the company renamed itself U.S. Rare Earths Inc. in 2008 and focused on mining the metals at Lemhi Pass and sites in Colorado.

Cowle's company and others are urging Congress to help fund domestic rare-earth mining and processing. U.S. Rare Earths spent $60,000 on lobbying in 2009 and 2010. Meanwhile, a Missouri-based mine is calling for a joint public-private-financed "universal" processing facility, which could cost $1 billion but would be available for all mines.

Members of Congress are already working to address the gaps in supply, infrastructure and know-how. Sen. Mark Udall, D-Colo., has introduced a bill that would create federal educational and research and development programs for "critical materials," including rare earths, with an emphasis on clean energy. Rep. Mike Coffman, R-Colo., just reintroduced a bill which lays out a similar national program oriented toward stockpiling reserves for defense purposes. Yet another, from Rep. Leonard Boswell, D-Iowa, would create a rare-earth research program and extend government loan guarantees for mining and processing to facilitate operations.

Government estimates suggest that the country could add up to a dozen rare-earth mines in addition to Mountain Pass to meet projected global demand, which is expected to increase as countries embrace clean energy technology; current supplies of metals used in wind turbine magnets could be depleted by 2020.  If a coordinated national program gets under way, reserves and a supply chain could be built up within 15 years, observers say. But it depends on how many of the new Western mines prove productive and financially viable.

Most of the rare earth deposits, outside of Mountain Pass and Bear Lodge, are believed to have relatively low concentrations. That could prevent several mines from ever opening, though Burnell notes that rare earths can be mined alongside gold, iron, titanium, or other resources.

"In the long run ... we're not looking at anywhere near the tonnages for rare earths that we see for gold," says Virginia McLemore, an economic geologist with the New Mexico Bureau of Geology. "It's highly specialized, and it's going to require a lot (of effort and infrastructure) compared to what we've got mining now. It's an especially tight market."