The Thacker Pass Deposit is located within an extinct supervolcano (30 km by 40 km) named the McDermitt Caldera, which formed 16.3 million years ago and is associated with the Yellowstone volcanic hotspot. For a few hundred thousand years following the volcanic eruption, water percolated through nearby volcanic rocks resulting in the natural leaching of lithium. The lithium was then deposited in the caldera basin, forming a large caldera lake and a thick sequence of associated lacustrine deposits.

Renewed volcanism uplifted the center of the caldera, draining the lake and bringing the lithium-rich sediments to the surface of the earth in the vicinity of the present-day Montana Mountains.

Recent drilling confirms that the lithium mineralization is extensive throughout the caldera, which suggests that the formation of lithium-rich clays is not due to a localized hydrothermal process like that which occurs in epithermal mineral deposits. The lithium mineralization is instead stratiform, resulting from primary deposition of clays and subsequent diagenesis. In the project area, lithium-rich clays range in depth from a few meters up to 90 m. They are typically overlain by alluvium with an average thickness of approximately 5 m and underlain by hard rhyolitic volcanic rock. Interbedded with the lithium-bearing clay are volcanic ashes and a small volume of interbedded hard basaltic beds. Basaltic rock increases in volume towards the southeast of the project area. Mineralogically, the upper clay horizons are dominated by smectite-type clay, while the deeper horizons are dominated by illite-type clay, with the latter showing mineralization of up to 9,000 ppm, and the former up to 4,000 ppm.

Lithium Americas is engaged in an exploration program to expand the resource in the vicinity of the proposed pit area. In 2017, Lithium Americas identified a new target area south of the proposed pit area called the Southwest Basin. Exploration assay results, published in the May 2017 Technical Report, demonstrate that lithium mineralization in the Southwest Basin occurs at grades and depths similar to the proposed pit area. Recent seismic surveys and ongoing exploration drilling aims to increase the confidence of the Southwest Basin resource and define the total extent of lithium mineralization throughout the McDermitt Caldera south of the Montana Mountains.

On October 7, 2021, Lithium Americas increased the Mineral Resource extimate to 13.7 million tonnes of lithium carbonate equivalent (LCE) grading 2,231 parts per million lithium (ppm Li) of Measured and Indicated and 4.4 Mt of LCE grading 2,112 ppm Li of Inferred Resources.

The sedimentary-clay deposit at Thacker Pass will use similar mining techniques to many coal deposits. The shallow (average depth of 300 ft), open-pit will be mined in blocks and actively reclaimed. Once one block is mined to the bottom , mining will move to the next block while backfilling begins in the previously mined area. The backfilled pits would then be capped with topsoil and revegetated with native species.
Block mining allows us to reclaim the land quickly and only have a fraction of the pit exposed at any given time. This will minimize long-term visual impacts and allow for substantial restoration of pre-project land uses by wildlife.
In 2019, we entered into a mine design, consulting and mine operations agreement with Sawtooth Mining, a subsidiary of North American Coal. Sawtooth Mining has exclusive responsibility for the design, construction, operation, maintenance, and mining and mine closure services for Thacker Pass.
North American Coal has over 60 years of surface mining experience and manages reclamation for over 200,000 acres under regulatory permits. Their extensive reclamation history has earned them over 94 federal and state awards in the last 30 years, which includes reclaiming 61,000 acres of land, reconstructing over 54.5 miles of streams and over 1,449 acres of wetlands and planting over 8.8 million trees.

The production process is designed to use conventional and commonly-available equipment, arranged to take advantage of the distinctive qualities of the high-grade ore.  The process comprises a series of steps to concentrate, separate and produce battery- quality lithium chemicals.
First, ore from the mine will be crushed, screened and then transferred as a slurry to the leaching circuit where sulfuric acid will be added to attack the ore and liberate the lithium from the clay. The high-grade quality of the ore allows for leaching to occur in stirred reactors (vats), specifically designed to maximize speed and efficiency of lithium dissolution, while minimizing sulfuric acid consumption. Total leaching time is estimated at three hours.
The resulting lithium-bearing solution will then go through a pH-neutralization step. Neutralization will be achieved with ground limestone during start-up and sustained with recycled alkaline solids from an upstream precipitation process during normal operation. Next, the lithium solution will undergo a crystallization step using steam and electricity from the sulfuric acid production process. Water is removed for recycling, and magnesium sulfate (Epsom salt) is produced. Any magnesium remaining in solution is removed in a second step that involves the addition of reagents to precipitate magnesium hydroxide.
Finally, soda ash will be added to the lithium bearing solution to produce a high-quality, battery-grade Li₂CO₃. Much of the water contained in the lithium solution will be recovered and returned to the process.  The total time projected to manufacture battery- quality Li2CO3 from the ore is less than 24 hours. The overall recovery of lithium from the ore is 83%.
The Company is advancing engineering to consider a 20,000 tpa lithium hydroxide chemical conversion plant to have flexibility to meet potential customer and partner needs.

We believe that collaboration with our stakeholder groups and adherence to local, national and international standards for environmental and social performance are paramount to our ability to drive improved environmental, social and financial outcomes.
Thacker Pass was designed reflecting information collected during numerous stakeholder meetings, including public open houses and ongoing engagement. This approach is expected to mitigate potential concerns at the design level, and ensures the local community is included early in the development process.  Future public open houses are planned as the project advances to ensure the community is fully engaged throughout the entire process.

We began early engagement with the Fort McDermitt Paiute and Shoshone Tribe, who are located about 20 miles away. We have formed long-term relationships with Tribal members and have encouraged members to consider future employment at Thacker Pass.
In 2019, a Cultural Technical Report was completed, providing a cultural-resource inventory covering 12,963 acres of land in the vicinity of Thacker Pass and lays the foundation for cultural-mitigation work to be conducted upon the commencement of operations.
We are committed to employing locally and working with local service providers to the greatest extent possible. We pay wages approximately twice the state average, in order to attract and retain quality employees, and provide high standards of living. We have surveyed the qualifications of community members to better understand the current labour available. We look forward to offering extensive training to minimize the use of outside labour.
We have partnered with Northeastern Nevada Regional Development Authority, Great Basin College, JOIN Inc. and Nevada Builders Alliance to leverage local resources and build capacity in the regional workforce.

Environmental leadership is a core value of Lithium Americas. Thacker Pass has been engineered to minimize the environmental footprint, by avoiding sensitive environmental habitat and employing the best available environmental control technologies.
Over a seven-year period, we collected baseline environmental data required for the National Environmental Policy Act (NEPA) process and have developed comprehensive plans to mitigate impacts to wildlife, water and air. Extensive monitoring will be conducted during operations. .
Thacker Pass will draw less than 1% of the total approximate 325,000 acre-feet per year pumped from Humboldt County. All process water will be recycled in a closed-loop cooling circuit, as a cleaner alternative to evaporation coolers, allowing us to save more than 1,000 acre-feet of water each year.
By entering into agreements with two ranchers to utilize the State of Nevada Conservation Credit System, we’ve mitigated any potential indirect impacts to Sage Grouse, even though studies completed to date do not anticipate direct or indirect impacts to Sage Grouse.
We established the Great Basin Sagebrush Restoration Fund in 2017 with the University of Nevada, Reno to develop technologies that improve desert restoration so we will be better equipped to reclaim the land concurrently during mining. In fact, the coated seed technology developed through our funding is now being commercialized for others to use. More information about the Sagebrush Restoration Fund can be found here
https://naes.unr.edu/rangeland_ecology/great-basin-sagebrush-restoration-fund/

Lithium production from Thacker Pass could enable a US domestic supply chain, bringing down the overall carbon emissions , transport costs and risks associated with manufacturing lithium-ion batteries.
Currently most of the world’s lithium is mined in Australia or South America and only 1% is mined in the US. Lithium concentrate is shipped mostly to China, to be processed into battery chemicals. These lithium chemicals are then often shipped to other parts of Asia, the US or Europe to make into cathodes and install in battery packs. The batteries are then often shipped to another location for installation into their final product, such as electric vehicles.

In 2020, Lithium Americas joined a coalition of 30 companies to launch the Zero Emission Transportation Association (ZETA), an organization dedicated to achieving 100% electric vehicle sales in the US by 2030. ZETA’s objective is to secure American global EV manufacturing leadership, dramatically improve public health and significantly reduce carbon pollution.

The Company achieved a key milestone with the receipt of a Record of Decision (ROD) from the US Department of the Interior Bureau of Land Management (BLM) on January 15, 2021. The ROD represents the final material permit for the Thacker Pass Project at a national level.
In February 2021, claims were filed against the BLM to appeal the issuance of the ROD for Thacker Pass. The Company has been advised of a hearing date set for Q1 2022.
Early-works construction is expected to commence in 2022, following the receipt of remaining state permits and water right transfers, and resolution of the appeal. Early-works includes site access and preparation, water line and additional infrastructure to condense and de-risk the overall construction schedule.