An Archaeology of Trees

If you’re one of the many Canadians spending this week sitting around a cut and dressed evergreen in the house, you’re part of an age-old human relationship, a unique tradition we have of mucking about with trees.

Trees are a material cornerstone of pre-industrial cultures. In precontact BC, both interior and coastal peoples relied heavily on trees for raw material, even food. Because trees have the ability heal after material and food are extracted, our forests still hold the evidence of these uses, if you know what to look for. These distinctively scarred trees are referred to as culturally modified trees (CMTs), and are a unique and disappearing kind of archaeology.

So what were people doing with these trees? In short: everything. In the way that hunting people expertly use every part of an animal, forest people expertly use every part of the tree: from fresh fir fronds for bedding and sweeping, through the woody trunk for building, all the way down to the teeniest stretchy rootlets for stitching and basketry.

Bark from cedar, sage, juniper and cottonwood was removed with bone and antler peelers, shredded and pounded until soft, then woven into textiles.

The sappy cambium (inner bark) of pine was eaten fresh in the spring, peeled from the tree in long juicy “noodles”. Late-season cambium, less sweet and tasty but flexible and with important antibacterial properties, was used as a packaging for food and bone implements.

Pine, spruce and subalpine fir (known also as balsam) were sought for their sticky pitch, used as a sealant and also as a powerful medicine for lung ailments.

Long, gently curved branches of Rocky Mountain juniper and Saskatoon were sought for bows, and often the same tree was used year after year, leaving a trunk peppered with smaller cut branches.

The wood itself, useful for so many purposes, could be obtained by falling whole trees or removing parts. The amazing western redcedar, central to the culture of Northwest Coast peoples, is uniquely suited to wood harvest: whole planks can be removed from live trees, which can be left standing for future use.

Standing trees are also a medium for art and communication: images carved into the trunks have been interpreted as guardians, territorial markers or simply artistic expression.

All these uses leave distinctive scars that slowly heal as the CMTs continue to live and grow, becoming living artifacts for archaeologists to study.

Entire trees, cedar on the coast and cottonwood in the interior, were felled and then carved and steamed into shape to be used as sturdy canoes. Tall, straight cedar were carved into iconic coastal totem poles.

These uses leave behind only the stump, or heaps of wood chips from carving that can be preserved in wet conditions and remain identifiable for centuries.

Harvesting these all products requires special attention to season, growing conditions, tree health, age and size. Trees were carefully chosen for unblemished bark, straight branches, or sound trunks, and specific locations in the forest that bred these qualities were revisited by generation after generation.

Archaeologists studying sites of modified trees can help recreate histories of Indigenous land use. Our ability to extract tree ring samples (using a tool called an increment bore) means that we can learn when the modifications were made, sometimes to the exact year.

As evidence of traditional practices that have waned since contact, these biodegradable artifacts are slowly disappearing through natural processes and modern forest harvesting. Keep an eye out for them when you’re next out for a walk in the woods-for now they’re still out there, hiding in plain sight.

Gitxsan arborglyph, Michael Blackstock photo.png
cedar bark slab, BC Archaeology Branch photo.jpg
bark stripped lodgepole pine CMT, Joanne Hammond photo.jpg