Tag for lumbermills/woodmills/pulpmills

A quick look on taginfo suggests that there is no established specific usage for tagging timber processing facilities. I've had a quick look to see if any I know about are tagged on OSM (for instance around Howe Sound, BC, Canada), but again drew a blank.

You are not alone with this issue because there are 1789 objects tagged description=timber production, which suggests we need a proper way of tagging this, and, indeed other specific industrial sectors.

I would suggest that you create an area for the bounds of the facility and tag this landuse=industrial. Individual buildings and processing areas can also be mapped if aerial photography is available.

Further tag the area with something like one of these : industry=sawmill (3 uses), industry_sector=timber_processing, industry:code=2400, ref:industry_code=2400. These different means of tagging have been used only a few times (industry=* is the most popular with a 100 uses), but all are trying to achieve the same thing. Most make use of the (International) Standard Industry Classification, which is a) public domain as originated by the US government and b) saves having to think of ones own classification. However, there is no obvious consensus yet.

As industry is the most widely used then probably the best course is to go with industry=lumber_and_wood_products, ref:industry_code=2400. Adding the ref tag would mean that you could use a more precise definition for the industry tag (e.g., industry=pulpmill), but anyone interested in the looking at timber processing in general could use the ref tag to identify all related industries.

You may gain further inspiration by looking at some of the existing things tagged with 'description=timber_production' (see taginfo link above).