Weyerhaeuser came to Saskatchewan in 1986 with the purchase of Prince Albert Pulp Company, including the Prince Albert Pulp Mill and Saskatoon Chemicals, from the Saskatchewan government. Through the transaction, Weyerhaeuser also acquired from the province a sawmill near Big River. As part of the acquisition agreement, Weyerhaeuser committed to construct an uncoated free sheet fine paper mill in Prince Albert. This was completed in August 1988; two sheeting machines to supply the customer-size sheet market were added in 1990 and 1991. Since 1986, Weyerhaeuser has upgraded its pre-existing Saskatchewan facilities. The largest investment was an economic and environmental enhancement project at Prince Albert Pulp & Paper, which was completed in 2000; this $315-million project reduced the amount of electricity and natural gas Weyerhaeuser purchases to operate the pulp and paper mill. In May 1999, the Wapawekka Lumber Ltd. sawmill was opened near Prince Albert, a $22.5-million joint venture between Weyerhaeuser and the Lac la Ronge Indian Band, Montreal Lake Cree Nation, and Peter Ballantyne Cree Nation. An extensive upgrade of Weyerhaeuser's Big River sawmill was completed in March 2001, which increased the sawmill's annual capacity from 90 million to 210 million board feet of dimensional softwood lumber.
On November 1, 1999, Weyerhaeuser acquired MacMillan Bloedel, adding two oriented strand board mills in Hudson Bay to its holdings in Saskatchewan: the Carrot River sawmill and the Hudson Bay plywood mill. The newer oriented strand board mill in Hudson Bay (OSB 2000) was officially opened in June 2001; this $200-million mill has annual production capacity of 600 million square feet of OSB. The Carrot River sawmill has capacity to produce 80 million board feet of stud-length lumber annually. The Hudson Bay plywood mill has an annual capacity of 112 million square feet of softwood plywood. In 2004, Weyerhaeuser directly employed more than 1,600 Saskatchewan residents at its manufacturing facilities, and was licensed to operate on 4.94 million hectares of forest in Saskatchewan.