what he said. Big pieces can be collected from fallen tree's, which has fallen suddenly in the spring. The roots will keep on pumping the tree remaining trunk full with resin. The older one's can be easily be spotted, because fat wood doesn't rot (well it takes awhile).

Other places are the spots where you can find resin saturated wood in pine are where the brandches are joint to the tree and the large roots from pine tree's.
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