The Whirlwind royalty is a sliding scale gross overriding royalty equal to 2% - 4% of the gross value from the sale of uranium oxide (commonly referred to as “yellowcake”) and vanadium pentoxide (commonly referred to as “black flake”) derived from ore mined from the subject area and 2% of the gross value of other mineral products. Gross value is calculated as actual or deemed proceeds, less certain allowable deductions. In lieu of the royalty payment, URC may at its election, on an annual basis, take its royalty as an in-kind production royalty of ore or concentrates for both yellowcake and blackflake directly from the Whirlwind mine site.

The Whirlwind Royalty does not apply to the entire project area for the Whirlwind Project. The royalty currently applies to approximately 320 acres, or approximately 11% of the currently defined project area.

In its Annual Report on Form 10-K for the year ended December 31, 2022, Energy Fuels stated that exploration drill projects were conducted in 2007, 2008, 2009, 2010, 2011 and 2012 on the Whirlwind Project. Evaluation of the property in 2019 indicated that the existing decline, rehabilitated in 2008, needs some additional rehabilitation work. Energy Fuels further stated that rehabilitation work on the decline was expected to occur during spring/summer of 2022, and that Energy Fuels’ conventional projects are expected to remain on standby until market conditions improve or are in the evaluation or permitting process.

Ores in this and other parts of the Uravan Mineral Belt were mined intensively in the early 20th century for radium (about 1914 – 1923). The Gateway/Beaver Mesa District of the Uravan Mineral Belt was mostly idle from the 1920s until about 1937 when several mills were built to process the ore for its vanadium content. Uranium became the emphasis of the district when the U.S. Army’s Manhattan Project came to the area in 1943. The U.S. Atomic Energy Commission (“AEC”) purchased concentrates from the several area mills from 1947 through 1970. Mining diminished until the mid-1970s when the private market price of uranium began rising to record levels. The area boomed until 1985 when the uranium price decline brought on by the Three Mile Island nuclear plant incident made most mining here unprofitable. When the price of vanadium experienced a brief spike in 1989-1990, several mines in the Uravan Mineral Belt were reactivated, including some on the Whirlwind Property. The last underground mining within the property boundary was in 1990 when the Umetco contractor mined 4,200 tons at 0.44% U₃O₈ and 1.06% V₂O₅ from the west end of the La Sal No.6 area, accessed through the Packrat portal.

In the 1970s, the area covered by the Whirlwind claims was held by several entities. The resources of the Whirlwind Mine were developed by Pioneer Uravan, which did not control any of the nearby mines that had portals in the canyon rim. Umetco, who controlled the Packrat and several other mines to the north, acquired the property from Pioneer Uravan in about 1984. Cotter Corporation staked the same area later in 1994 as the Liberty group. Neither Umetco nor Cotter did any underground work in the mine. Cotter conducted a small drilling project which resulted in a minor increase to associated vent holes, and Cotter reclaimed its Liberty Mine (Whirlwind) portal in the next few years. As the uranium and vanadium prices began increasing in 2004, Lee Sutherland of Little Maverick Mining Company staked new claims beginning in January 2005, covering the old mines and an area of indicated mineral resources. The claims of the Whirlwind group include the Packrat, part of the Hubbard, and some of the Lumsden group of mines, as well as the La Sal and southern end of the Bonanza mine areas.

When initial development was stopped in September 1981, there were two main headings in the Whirlwind Mine. The Whirlwind Mine has been rehabilitated to both faces and the main haulage drifts enlarged to accommodate larger haul trucks. Due to the declining uranium price, the mine was placed on standby following the rehabilitation work in late 2008. In order to conserve cash, a decision to stop pumping and treating water was made in December 2009.

Energy Fuels has disclosed a resource estimate under NI 43-101, which included indicated resources of 1.10 Mlbs U₃O₈ and 3.60 Mlbs V₂O₅ in 188,000 tons of ore grading 0.29% eU₃O₈ and 0.96% V₂O₅, respectively, and inferred resources of 2.00 Mlbs U₃O₈ and 6.47 Mlbs V₂O₅ in 437,000 tons of ore grading 0.23% eU₃O₈ and 0.74% V₂O₅, respectively. Such resources were estimated at a uranium cut-off grade of 0.06% eU₃O₈. This cut-off grade is based on using a long-term uranium price of $77.50 per pound U₃O₈ and a vanadium price of $7.50 per pound V₂O₅. Vanadium grades are based on assays where taken, and otherwise estimated at the average V₂O₅:U₃O₈ ratio of 3.24:1.