Lumber prices finally cooled off. Now come the fires. Forest fires raging in the West are threatening an important swath of the U.S.’s wood supply. …Canfor, one of North America’s largest lumber producers, said it would cut back output at its mills in British Columbia That is only a sliver of North America’s overall supply… yet analysts said they expected further curtailments. …Traders responded Wednesday by bidding up lumber futures for delivery through January. …Random Lengths said that some Western mills have recently unloaded two-by-fours below $400 per thousand board feet. Forest-product executives said that mills operating in BC usually need more like $700 to be profitable these days. Such a high break-even price, along with the threat of fires and distance to the Sunbelt’s mushrooming housing markets, has relegated what was once the continent’s top lumber-producing region to the status of swing producer. (to access the full story, a WSJ subscription may be required)