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Canada

Grassy Mountain Project

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Summary

Mine TypeOpen Pit
Study CompletedPrefeasibility
StagePermitting
Commodities
  • Coal (metallurgical)
Mining Method
  • Truck & Shovel / Loader
SnapshotGrassy Mountain is on the site of an old mine that closed about five decades ago. The new, open-pit mine that Benga Mining Ltd. proposed for the land forecast production of 93 million tonnes of metallurgical coal over a 23-year life.

A joint federal-provincial regulatory panel rejected the Grassy Mountain application in 2021, finding that the project would likely result in significant adverse effects on the environment.

Northback is seeking approval from the Alberta Energy Regulator (AER) for a Coal Exploration Program, a Deep Drill Permit and a Temporary Diversion Licence.

On May 15, 2025, the Alberta Energy Regulator approved a controversial coal exploration project. The decision grants Northback permits to drill and to divert water to the site.

It isn't an application to mine. Northback will be responsible for reclamation related to the exploration work.

As of September 2025, Northback to submit new proposal to develop Alberta’s Grassy Mountain coal mine.

Owners

SourceSource
CompanyInterestOwnership
Hancock Prospecting Pty. Ltd. 100 % Indirect
The Grassy Mountain project is being led by Northback Holdings, formerly known as Riversdale Resources and Benga Mining, and Hancock Prospecting is the parent company.

Deposit type

  • Sedimentary

Summary:

The coal seams of the Project are medium volatile bituminous in rank and found within the Mist Mountain Formation of the Kootenay Group, which is Jurassic to Lower Cretaceous in age. The coal sequences in the Mist Mountain Formation consist of a cyclic succession of carbonaceous sandstone, mudstone, siltstone, coal, and some conglomerate. The main coal zones identified within the Mist Mountain Formation in this area, from top to bottom, are Zones 1, 2 and 4. Coal Resources and Coal Reserves estimates take into account the two thickest seams from Zones 1 and 4 and the single thickest seam from Zone 2. Zone 2 contains the thickest single seam.

Grassy Mountain coal in the Mist Mountain Formation outcrop occurs in a general north-south direction for a strike length of approximately seven (7) km. The Mist Mountain Formation consists of 66 to 194 vertical metres of strata and is overlain by prominent, weather-resistant Blairmore conglomerate. The strata have been strongly folded and faulted, resulting in sediments and coal zones repeated in parallel bands. Coal deposits of this type are characterized by tight folds, some with steeply inclined or overturned limbs. Fault offsets are common but fault-bounded plates generally retain normal stratigraphic thicknesses. These characteristics suggest that the Grassy Mountain coal deposits should be categorized as “Complex” to “Severe” Geology Types.

Reserves

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Mining Methods

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Heavy Mobile Equipment

Fleet data has not been reported.

Comminution

Crushers and Mills

Milling equipment has not been reported.

Processing

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Commodity Production

CommodityUnitsAvg. Annual
Coal (metallurgical) Mt 2.5 *
All production numbers are expressed as clean coal. * According to 2025 study.

Production Costs

Commodity production costs have not been reported.

Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Nov 12, 2025

Workforce

Total WorkforceYear
...... Subscription required 2025

Aerial view:

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