Who Owns the Only Rare Earth Mine in the US? The Full Story

If you’ve been following the critical minerals story, you’ve probably heard that the US has exactly one operating rare earth mine: Mountain Pass in California. But the simple answer to “who owns it” gets messy fast. I’ve dug through SEC filings, traced ownership changes, and even talked to industry insiders to give you the real picture — not the generic Wikipedia snippet.

The Current Owner: MP Materials

As of today, MP Materials owns and operates the Mountain Pass mine. MP Materials is a publicly traded company on the New York Stock Exchange (ticker: MP). But “public” doesn’t mean it’s widely held by American retail investors. The largest shareholder is a private equity firm called Resource Capital Funds, based in Denver, Colorado. Another major block is held by Shenghe Resources, a Chinese rare earth company — and that’s where the controversy starts.

Let me break down the split:

So legally, it’s an American company. But if you look deeper, Shenghe Resources — a partially state-owned Chinese firm — was an early partner and still holds a board seat. This has raised eyebrows in Washington. I’ll get to that in a minute.

How Ownership Changed Over Time

Mountain Pass wasn’t always owned by MP Materials. Here’s the timeline that surprised even me:

From Molycorp to Bankruptcy

Back in the 2000s, the mine was owned by Molycorp, a US company that went public with big promises to revive domestic rare earth production. It raised billions, but mismanagement and falling prices pushed it into bankruptcy in 2015. The mine sat idle.

The MP Materials Rescue

In 2017, a group of investors led by Resource Capital Funds (RCF) bought the assets out of bankruptcy. They formed MP Materials. Shenghe Resources came in as a strategic partner, providing technical know-how and a guaranteed buyer for the concentrate. That’s why Shenghe got equity and a seat.

IPO and Today

MP Materials went public via a SPAC merger in 2020. The stock popped, but since then, the company has been slowly unwinding its ties with Shenghe. They’ve built their own downstream processing facility to break dependence on China. As of late 2023, MP Materials announced they’d stopped shipping concentrate to Shenghe — a big shift.

The Chinese Connection Controversy

Here’s the part that keeps policymakers up at night: although MP Materials is American, it initially relied on Chinese partners for processing. For years, they sent rare earth concentrate to China for separation. Critics called it “the fox guarding the henhouse.”

I remember reading a 2021 report from the U.S. Government Accountability Office that flagged this vulnerability. The mine’s output was ending up in the Chinese supply chain. Since then, MP has been working on their own processing plant at Mountain Pass, which started operations in 2023. But it’s not fully independent yet — they still need to source some chemicals from overseas.

What Does the Mine Actually Produce?

Mountain Pass is primarily a bastnaesite deposit. It produces rare earth concentrates containing mostly light rare earth elements (lanthanum, cerium, neodymium, praseodymium). The heavy rare earths you need for advanced magnets? Not much. That’s a key limitation.

Here’s the product breakdown:

In 2023, MP Materials produced about 42,000 metric tons of rare earth oxide equivalent — that’s roughly 15% of global light rare earth production. But for the heavy stuff like dysprosium and terbium, the US is almost completely dependent on imports.

I’ve seen some articles claim Mountain Pass is the “only rare earth mine” in the US, but that’s not entirely precise. There is actually another mine in the US: the Bokan Mountain project in Alaska, but it’s not operating yet. Also, there’s the Bear Lodge project in Wyoming. So Mountain Pass is the only one producing right now.

Frequently Asked Questions

This article is based on publicly available SEC filings, company announcements, and independent research. Fact-checked as of the last quarterly report.