Aerial scans of the Earth's crust 3,300 feet below ground are being used to seek out potential critical mineral deposits in Cowboy State.

Using an array of sensors attached to aircraft flying overhead, geologists are scanning thousands of feet below Wyoming's surface with electromagnetic surveys – a prospecting method that reads the strength of the earth's subsurface magnetic field to identify likely locations of valuable metals and minerals like vanadium, niobium and tantalum.

While this Earth-scanning mineral exploration technology is not new, the scale and detail of the survey being carried out over Wyoming by the U.S. Geological Survey in partnership with state geologists is unprecedented.

"The resolution is new," Wyoming State Geologic Survey geologist Chris Doorn told Cowboy State Daily in a press interview. "This is the first time to have this high of resolution for data that will be available to the general public. It will be free and available from the USGS website."

The detailed electromagnetic and other geophysical surveys being flown over Wyoming are part of USGS's Earth Mapping Resources Initiative, a nationwide program better known as Earth MRI, a clever moniker that reflects the earth-penetrating scans that provide geoscientists with images of the rocks hidden below the surface.

"Rocks have different properties, and these surveys can measure that," said Doorn. "Rock density, magnetic strength, porosity, electrical conductivity and things like that. These geophysical surveys measure these properties."

The objective of these MRI-like scans in Wyoming and across the nation is to find new sources of minerals critical to the nation's economic and national security, but do not have a domestic source, making them vulnerable to disruption of supply.

Wyoming strikes it big

Wyoming is a potential source for at least 39 of the 50 minerals officially deemed critical to the U.S. This includes rare earths, a suite of 15 elements that are more abundant in the Earth's crust than their name suggests but are typically found in low concentrations interspersed with each other and more common minerals, making their separation and refinement difficult.

Within this group of 15 lanthanide elements, some are truly rare, and it appears Wyoming has been the lucky recipient of a growing number of potentially commercial-scale concentrations of these tech-critical elements.

American Rare Earths Inc. has its sights on thousands of acres near Wheatland, disclosing a technical report finding 2.34 billion metric tons – 64% more than it had originally envisioned in a 2023 assessment of the land – dwarfing Ramaco Resources' own impressive discovery in Sheridan, an estimated $37 billion bonanza of 1.2 million metric tons of REEs.

American Rare Earths' Halleck Creek project in Wyoming has since been named one of the world's top 10 rare earth projects by Mining Intelligence. The project is underway and aims to begin operations in about five years.

American Rare Earths have also identified a significant REE deposit in Beaver Creek, with observed grades of lanthanum, cerium, neodymium, praseodymium and yttrium.

Bear Lodge deposit near Sundance is also being considered a prospect for commercial-scale production by Rare Element Resources Ltd., demonstrating economic percentages of cerium, lanthanum, neodymium, and praseodymium.

It is ideally located in northeastern Wyoming with easy access to power and supporting infrastructure. The company is in the final stages of installing a rare earth processing and separation demonstration plant in Upton – the first step in a commercial plant in Wyoming that will separate rare earths into the individual elements critical to high-tech, clean energy, and other sectors of America's economy.

Flying friendly skies

The Earth MRI surveys scanning Wyoming for rare earths and other critical minerals use helicopters to fly mountainous terrain, and fixed-wing aircraft for flat land. Magnetic data can be measured as far as 3,300 feet below the surface of the earth from roughly 330 feet high in the air, while radiometrics can identify natural radiation from elements like potassium, thorium and uranium from the top few inches of ground surface.

"We have data so far from the South Pass and Seminoe mountains," Doorn said. "And we completed a survey covering Medicine Bow Mountains as well."

"There's a wide variety of rock types in the Medicine Bow. A lot of them are metamorphic and igneous." Doorn said. "There's also potential rare earth elements in the Medicine Bow as well as tantalum and niobium, and a whole host of other potential critical minerals there."

The mining industry is keeping an eye on the aeromagnetic and radiometric Earth MRI scans of Wyoming, with some already partnering up to widen the scope of the surveys.

"We have gotten interest in the area of southeast Wyoming," Wyoming State Geological Survey's Erin Campbell told Cowboy State Daily. "We have one company, whose name will remain confidential, who is partnering with us to increase the area of the survey so we can fly more detailed and more closely spaced lines over their area of interest, and they'll keep that data confidential for a year while they expand their claim."

Companies exploring the area have also contributed data helping to direct the surveys to the South Pass area over Granite Mountain to the Seminoe Mountains.

"We have emails from them explaining how the data has helped them refine their claims," Campbell said. "And one thing we did for the central Wyoming survey is we canvassed industry to see where they'd like the data flown. This program has one to two years of funding left in it at this increased rate. The program had a baseline funding that was not very large, but the Bipartisan Infrastructure and Investment law increased it by $510 million. That expires in 2026."

The Earth MRI scans help to pinpoint the best locations of the Cowboy State for geologists to get their boots on the ground to sample rocks and discover concentrations of critical minerals high enough to entice further exploration. Funding for these surveys has come from both USGS and Wyoming.