Bears are curious, persistent, and tremendously strong creatures. Given enough time they can break into just about any structure to ransack it in their quest for food.
And if you travel enough in bear country you’ll inevitably come across some pretty elaborate fortifications that people have built to protect their cabins.
One of the lowest tech items that is still very effective is the so-called ‘bear board’, also known as an ‘unwelcome mat.’
A bear board is a typically made from a 1/2″ to 3/4″ sheet of plywood pierced with screws or nails, placed on the floor or a deck, pointy sides up to protect doors, windows, and other weak points. I’ve usually seen half sheets (4’x4′) to full sheets (4’x8′) of plywood used to protect doors
The idea is that if a bear tries to break in he’s going to get a very sore foot or two. The goal of those nails is not to injure the bear, just to deter it.
You do need to be careful yourself, because let’s say you approach an uninhabited cabin in the middle of the night, perhaps looking for shelter, and step on one of these damn things… You could be seriously hurt! Do be aware of these traps.
Often bear boards are just laid there, but in some areas these boards are actually screwed down into the deck in a few places to stop the bears from moving them. I have seen some cabins completely destroyed where a canny bear managed to get his claws under a board and flip it over.
Colorado’s guidelines for unwelcome mats uses nails that protrude 3/4″ to 1″ from the board. That means for a plywood board 1/2″ thick you’d be using nails 1 1/4″ to 1 1/2″ long. Remember, the point of these mats is not to maim the bear with the nails, just to hurt their feet enough so that they retreat ane look for food elsewhere.
The measurements above apply to black bears. Unfortunately bigger bears do require bigger nails, and in the Churchill area where cabins can be attacked by both grizzly and polar bears it’s not uncommon to see 4″ nails being used.
The most fortified building I’ve ever seen, with bear boards in front of the door, on the door, on the windows, and a gigantic steel latch to hold the door shut, is Jack Batstone’s cabin at the mouth of the Seal River on Hudson Bay. Not coincidentally this is an area with TONS of polar bear – we saw 14 of these dinner table sized bears in a 24 hour period near the cabin in 2021.
Bear safety is an important topic in the wilderness. Click here to see the other articles I’ve written about living and travelling safely in bear country.
And click here for updates on my 1000 Mile Solo book, the account of my journey from black bear country to tundra grizzly country to polar bear country.