A little about CMTs in general

Aoidhne de la Foret (aka Anne deForrest Ketchin, PhD) Copyright 2025

Culturally modified tree is an archaeological term for trees modified in certain ways by humans, for many cultural reasons. As an archaeological term, it refers to trees modified in the past, especially to the work of ancient indigenous peoples. The practice is still very important to many Indigenous cultures who, today, live on Reservations all over the world. Tree modification has been practiced by these First Peoples on all continents (and many islands) with trees. An exception is Antarctica…… No trees. Oral histories, linguistic research, and fossils suggest the practice is thousands of years old.

Around fifty culturally modified Ponderosa Pine live among us in the Zapata Subdivision. Those here are similar in age and appearance to the many CMTs in Indian Grove  in the Great Sand Dunes National Park and Preserve. When applied to the trees in the ZHA and the Dunes Park, CMT refers to the work of certain American Indian cultures before and during European colonization and settlement. Through their oral histories, these American Indian cultures trace their belonging in the Great Sand Dunes and Zapata Subdivision area for thousands of years. These are the three Ute Tribes (two in Colorado and one in Utah), some Pueblo groups of the Northern Rio Grande in New Mexico, and the Jicarilla Apache People of northern New Mexico.

You may hear the term “Peel Tree”, because the most obvious human modification is the removal of a section of the tough and thick outer bark. The “peel”. The care and skill evident in the modifications show just how knowledgeable these First Peoples were, and are, about trees, and forestry in general. The peels are intentionally shaped, and carefully done so as not to harm the tree. They are unlike lightning strikes, road work damage, animal chews and claw marks, or splits in the outer bark due to weather.

Aoidhne de la Foret (aka Anne deForrest Ketchin, PhD) Copyright 2025

Why peel a tree?

Each specific culture has its own reasons for peeling a tree. Generally reasons include both practical and spiritual. For most ZHA readers, practical purposes seem like a separate category from spiritual purposes. This is not the case for the cultures who made CMTs.

Peels were (and where still practiced, are) made during spiritual ceremonies, even when primarily for food, or for other raw materials. Prayers sung and thought were “put into” the tree.

• Practical — Removal of a section of the tough outer bark (periderm) allows access to the vascular tissue of the tree, the food transport tissues (Phloem or inner bark, and xylem or sapwood). This part of the tree carries the nutritious juices and other essentials from root to crown (xylem) and crown to root (the phloem). In between is  the cambium, a thin layer of undifferentiated cells that can become either phloem or xylem as needed. The cambium is only a couple of cells thick and so is not visible without a microscope. (As phloem/inner bark and xylem/sapwood age, old phloem becomes outer bark. Old xylem becomes heartwood.) Inner bark and cambium are nutritious to humans and other animals, not just to the tree! The sap (water and minerals along with resins) is also nutritious and useful, but includes resins that make knowledge and careful preparation necessary. The tough outer bark removed by the peeling is not wasted. It, the sapwood and heartwood are useful for shelter, fire starter, and cradle boards and lots more.   

• Spiritual — In general, the spiritual reasons for peeling a tree include communication with spiritual realms, healing, commemoration of important people, deaths, births, prophecies, communication with members of one’s own Tribe as well as other Tribes, and much more.

How to visit a CMT — Each CMT could be understood as a prayer reservoir. Please keep this in mind as you approach and visit one. Please treat the tree and its surroundings as you would want your personal special place treated.