The Company began operations as Western Collieries Limited in 1950 – becoming one of three mining companies on the Collie coal fields. First production came from an open cut mine called Collieburn, followed by the development of two underground mines in 1952.
Consolidation of the Collie coal mining industry to two producers in 1960 was the start of a rationalisation that culminated in the purchase of the Company by Wesfarmers in 1989. Underground mining ceased in 1994 but production increased with the commencement of the Premier Mine in 1996, which continues to produce to this day. The Company was acquired by Yangzhou in 2011 and has been managed by Yancoal Australia since then.
Total production from 1950 to 2016 has been in more than 100 million tonnes.

After WWII, most of the Collie coal mines were coming to the end of their lives and further exploration for resources and new mine development was required. The scarcity of timber on the Goldfields, due to harvesting for fuel, prompted the formation of a Syndicate in 1947 to develop coal leases at Collie to provide this energy shortfall.  

The "Goldfields Coal Syndicate" pegged 12 leases and 2 prospecting areas. A drilling program quickly identified several exploitable seams and in 1949 the Syndicate floated the newly formed Western Collieries Limited with a listing of 500,000 one-pound shares.

 Operations began in December 1950 at the Collieburn open cut with a contract to supply government to at least 1953. A Ruston Bucyrus 200W walking dragline was purchased for the princely sum of 90,000 pounds from the United States. It was to be used for overburden removal and was rated at 4 tons a minute. Coal was to be loaded with mechanical shovels and motor trucks.

By January 1952, Western 1 underground mine was in operation followed later in the year by Western 2 underground. Difficult mining conditions, such as water logged roof and floor materials, hampered the underground mines and eventually claimed the life of Western 1 in 1958, having only produced approximately 300,000 tons of coal.

Western 2 also had a chequered early life, encountering frequent, heavily saturated "washouts" and slurry runs, but managed to survive, eventually becoming the largest ever underground producer on the Basin.

In these early days, about 80% of the workforce were migrants - mainly from Poland, Italy and Germany. The company was quick to embrace mechanisation, in fact the Collie Coalfield was the most mechanised in Australia. Yet in difficult areas of Western 2, mechanisation gave way to hand mining.

Company growth saw the development of Western 3 open cut mine in 1954, using the dragline from Collieburn open cut, and Western 4 underground, in from the high wall of Western 3. Western 4 started production in 1958 using labour and equipment from Western 1. It had good coal but a short life due again to water problems.

The rise of imported oil, as a competitor to coal in the late 1950's and 1960's, saw major upheaval on the coalfields with the previously dominant company for 40 years, Amalgamated Collieries, losing the support of government contracts and closing its operations in December 1960. The result was two remaining companies, Western Collieries and Griffin Coal.

Construction of the Muja Power Station in 1966-69 helped stabilise the coal market and Western Collieries responded and expanded with further development. In early 1970, the Western 5 open cut mine commenced coal production.

A joint venture in 1971, with the Peabody Coal Company, was a pivotal move to explore the basin and provide greater confidence for future contracts. This work added considerable reserves - timely in that the oil crisis of the 1970's, causing the oil price to rise five-fold in three years, again put coal on the front foot.

For Western Collieries, a capital injection was required to embrace new mechanised technology. The takeover by CSR, started in 1975 and completed in 1980, accelerated technical development and mining mechanisation - ensuring the company's competitiveness - while the expansion of Muja Power Station, in 1979-85, contributed greatly to the security of coal utilisation. This was reinforced by the government signing a 20-year contract with Western Collieries in 1979.

For most of the Company's underground history, mining was by board and pillar with boards and cut-throughs typically about 6m wide and pillars 20m x 10m in dimension. Western 6 underground (1980) and Western 7 (1983) were opened and over the next few years, the underground mines embraced new, higher-efficiency equipment.

Continuous mining machines such as the Dosco Dintheader and Alpine AM50 Miners replaced the semi mechanised system of drilling and blasting, then loading with bobcats onto a scraper chain conveyor with the coal then transferred to belt conveyors for transport to the surface. By 1986, the continuous miners accounted for 75% of the total coal extracted (1,800 t/shift).

The signing of a 20-year contract, to supply 26 million tonnes of coal to Western Power until 2003, provided security for the mines and workforce of 800. A gas surplus, and stockpiling of coal by Western Power, was a warning of tough times to come. Meanwhile, Western 5 continued as the quiet achiever, embracing new and larger equipment, progressing to Demag excavators and larger 180-ton trucks.

WA company Wesfarmers Limited purchased Premier Coal in 1989, bringing a major capital injection and the introduction of new management.

The 1990's were marked by extreme pressure on the Company to improve productivity and lower the cost of coal. The threat from the emergence of natural gas as a competitor was to take its toll. Survival dictated major change and, in 1994, the deep mine operations were closed with a loss of 239 jobs - the first time in nearly 100 years' men would not be going underground on the Collie coalfields. This decision was quickly followed by a move to open cut mining 8km east in the Premier Sub Basin. The Premier Mine commenced prestrip in early 1995 while the Western 5 operations were wound down and closed during 1996.

Geology of the Premier Basin is considerably different allowing the use of larger mining equipment such as electric shovels, a first for the basin, and 240-tonne capacity trucks. Pits 3 and 1D exploit the Premier seams and Pit 5 exploits the Ewington seams.  The Premier seams are relatively flat allowing the use of the electric shovels, while the Ewington seams are steeply dipping, requiring a benched approach using hydraulic excavators.

The Premier Mine expansion, costing around $120M, enabled Premier Coal to successfully bid for the full supply of coal to the new Collie 'A' Power Station, starting in 1998. Part of this success was no doubt due to Premier's new coal plant with a rail-mounted, stacker-reclaimer system capable of significantly higher quality control than conical stockpiles used elsewhere in the Collie coalfields.

The company is continuing to press for improvement change in a strong commercial environment and rapidly changing energy market in Western Australia.