Flames broke out in the long-closed mill just before 10 p.m. (Mountain time) and a cause has not been determined.
A spokesman with the City of Cranbrook says firefighters realized they could not save the planer mill and instead worked to prevent the flames from spreading across the 36 hectare property.
Tembec closed the sawmill at the site in 1998, the planer was shuttered in 2010 and the kilns were permanently shut down in May.
The company received just over $100,000 from the Ministry of Forests in July to pinpoint and clean up any contamination issues on the southeastern B.C. property, and testing was expected to begin before the end of this year.
A sale of mill assets, ranging from the drying kilns to office furniture, concluded in late September. (CHBZ)