The Williston (East Block) occurrence is located east of Butler Ridge approximately 21 kilometres north of the community of Hudson's Hope, in the Liard Mining Division.
The Peace River Coalfield extends nearly 400 kilometres along the Northern Rocky Mountain inner foothills from the Alberta border, 180 kilometres east of Prince George, to 130 kilometres north of Hudson’s Hope at Pink Mountain. Medium to low volatile bituminous coal seams of economic thickness and continuity are hosted by the Lower Cretaceous Gething (up to 1036 metres thick) and Gates (up to 280 metres thick) sedimentary formations of the Bullhead and Fort St. John groups, respectively. The Gething Formation represents the dominant coal-bearing strata north of the Sukunka-Bullmoose area (MINFILE 093P 001, 093P 014) west of Tumbler Ridge.
In the Williston East and West block licenses area, one main coal seam, the lowermost Gething seam, and a large number of thinner coal seams, most less than 1.0 metre thick, occur in the Lower Cretaceous Gething Formation (Bullhead Group). At this location, the formation is less than 300 metres thick and consists of sandstone, shale, siltstone, mudstone and minor conglomerate. Prominent sandstone, at least 30 metres in thickness and capped by a chert pebble conglomerate, marks the top of the Gething Formation in this area. The Gething Formation is deposited in well-developed cyclothems that range in intervals from 1.5 to 7.5 metres in thickness. A typical cyclic order of deposition consists of: dark grey mudstones and shales; shale and siltstones with sandstone interbeds; very fine to medium-grained sandstones; silty, sandy mudstones and argillaceous silty sandstone; lithified seat earths; black soft mudstones; and black fissile carbonaceous shale.
A few thin and discontinuous coal seams occur in the Upper Jurassic to Lower Cretaceous Minnes Group.
The regional structure trends northwest. In the East Block, the Bullhead syncline separates a thrust faulted anticline from the Bullhead anticline.
The coal is all of high volatile bituminous C rank with fair to good coking properties. Two samples from a seam, intersected at 22.5 to 25.6 metres in drillhole W1MH 81-11 in the West block of licenses (MINFILE 094G 025), contain 25.8 to 69.7 per cent ash, 11.4 to 19.4 per cent volatile matter, 16.2 to 52.9 per cent fixed carbon and 0.23 to 0.59 per cent sulphur on an air-dried basis and dried basis (Coal Assessment Report 688).
The Williston area was first explored in detail by Utah Mines Limited in the 1970s. This included the search for large reserves of metallurgical coal in the land north from Williston Lake along the Dunlevy syncline, past the Chowade River. In the Dunlevy Creek area, only one drillhole was drilled to a depth of 246 metres. This hole was abandoned before entering the bottom Gething-Dresser contact and cut 41 thin coal seams. In 1971, the area along the east slope of Butler Ridge was obtained by Amax Coal Company. They drilled four holes north of Ruddy Creek to depths of approximately 365 metres. Several coal seams were intersected with a few in the order of 1 to 1.5 metres.
By the early 1980s, the Williston area was being explored by Cyprus Anvil Mining Corporation and Hudson's Bay Oil and Gas Company Limited. In 1981, regional mapping and 11 diamond drill holes, totalling 1684.7 metres, were completed on the property. Three holes within the East block of licenses did not penetrate through the top of the Gething Formation, and no coal seams were intersected. In the West block of licenses, a 3.0-metre coal and shale interval was intersected in the middle of the Gething Formation, at a depth of 22.5 metres.
Exploration programs identified four potential areas, totalling a possible 35 million tonnes of clean coal. The largest area, south of Dunlevy Lake, had a possible regional reserve of 15 million tonnes; a possible 5 million tonnes was identified from the area on the west slope of Butler Ridge; another possible 5 million tonnes was identified from the Trojan seam on the east side of Butler Ridge; and a further 10 million tonnes was identified from syncline and anticline structures to the east of Butler Ridge (Property File - Cyprus Anvil, J. Loader, 1980).
In December 2010, the Government of British Columbia committed to develop a plan to manage the seven northern ecotype caribou in the South Peace River area. One project undertaken to assist development of the Peace Northern Caribou Plan was a modelling exercise to develop alternate development scenarios. This project integrated the available scientific information and expert opinion to predict the future abundance of caribou. It predicted future caribou numbers based on projections of industrial build-out by the coal, forestry, wind and oil and gas sectors. The report from this project, entitled "South Peace Northern Caribou Management Model", was completed in 2012 and is available at https://www.env.gov.bc.ca/wld/speciesconservation/nc/documents/Final_Wilson%20%202012%20%20PNCP%20management%20model.pdf.
