Image source: Cliffs Natural Resources

What: Cliffs Natural Resources Inc.'s (CLF -1.99%) shares rose by nearly a third last month, with a big leap in the last few days of trading. That said, the stock started June off strongly, too, so it was, on the whole, a good month for the North American iron ore miner.

So what: Cliffs started June with the announcement that it had inked a new supply agreement. That news was notable because it will allow the company to restart a mine two months earlier than expected. More important to the top- and bottom-lines, however, is the fact that this deal led the company to up its annual sales volume and production guidance by nearly 3% each.

So June started out with some pretty good news for a company that's been feeling a lot of pain as the North American steel industry, its main customer, has struggled to deal with a flood of cheap imports. There was more good news, however, at the end of the month.

That's when a pair of United States International Trade Commission (ITC) rulings came out that, basically, said certain imports from China, India, Italy, Korea, and Taiwan were being sold below fair value. That means imports from these countries can be hit with countervailing and anti-dumping duties. While this doesn't impact Cliffs directly, it should help to support demand from its main customers in North America and suggests a future that's getting brighter. Investors reacted positively to that news and sent the shares higher along with U.S. steel names.

Now what: The U.S. steel industry isn't out of the woods just yet and suppliers like Cliffs still have to worry about the often complex dance between imports and domestic steel production. So don't expect price volatility at Cliffs to subside. However, if you believe that the U.S. steel makers are starting to get back on their feet again, Cliffs is likely to be a notable beneficiary. In fact, the new contract inked in early June suggests things are, at the edges, starting to look a little brighter for this miner.