The first round of public comment for a proposed $500 million rare-earth mine will come to a close April 30.

According to the U.S. Forest Service, Rare Element Resources Ltd. in late March filed its intent to prepare an environmental impact statement (EIS) for the nearly 2,300-acre project that will incorporate an open-pit mine to extract rare-earth minerals. Work on the EIS had already commenced in late January, according to a company release.

The site has reserves of six out of nine critical rare-earth elements, with 80 percent of its ore value linked to those elements. These elements are tied inextricably to electronics manufacturing like high-definition TVs, smartphones and computer chips. Yet they also play an important part in health care, clean energy and even national defense according to the Rare Earth Technology Alliance.

Officials of Rare Element Resources say the mine will require a capital outlay of between $300 million and $500 million to get going, including the mine near Sundance and a processing facility in Upton, which is within 50 miles of the mine site. The mine would be the first built in the U.S. in more than 60 years.

Currently, China meets 90 percent of global rare-earth demands despite controlling only 23 percent of world reserves. In 2010, China set stringent export quotas for rare earths, saying the mining was being pursued illegally and causing environmental damage. But a World Trade Organization ruling indicated the restrictions are designed to give Chinese industry a leg up on competition by protecting access to some materials.

China's government-run newspaper, the People's Daily, offered up plenty to say on the topic in its editorialized voice.

"China's export restrictions have upset a number of overindulged countries that have become accustomed to enjoying low prices over a long period," the paper wrote. It also said other countries have blocked rare-earth "exploitation" on environmental concerns, indicating that "China will spare no efforts in appealing, but whatever the result, China's policy of protecting its resources and its environment is not going to change."

For Rare Element Resources, this mentality could present an opportunity.

"We believe the Bear Lodge Project is an important component of America's expressed desire to re-establish a secure, domestic source of critical rare earths, and we are committed to developing a project that meets the highest standards of environmental stewardship," said Jaye Pickarts, chief operations officer of Rare Element in a release.