A bearing tree is a specific type of tree utilized in land surveying as a permanent accessory to mark a boundary corner. It serves as a durable, identifiable reference point, or “witness,” for the actual monument set in the ground. Surveyors select a nearby tree and record its species, diameter, and the precise distance and direction from the corner marker to the tree. This process creates a lasting record that allows the original corner location to be recovered even if the primary physical marker is destroyed or moved.
The Function of a Bearing Tree in Surveying
Corner monuments, such as iron pipes, stone posts, or wood stakes, are susceptible to being dislodged, buried, or intentionally removed over time. The use of a nearby, living tree provides a secondary, more stable reference point that is less likely to disappear completely. This practice became standardized with the establishment of the Public Land Survey System (PLSS) for dividing vast tracts of public land. If the main corner marker was lost, the recorded information about the bearing tree allows a later surveyor to mathematically calculate and restore the exact original location.
This calculated position is determined by sighting the tree and measuring the recorded distance along the reverse of the recorded direction, or bearing. The initial instructions for these surveys required the recording of four such trees at standard corners, one in each quadrant around the monument. This triangulation provides redundancy, making the corner significantly easier to relocate decades or even centuries later. The species of the tree, its diameter, and the specific bearing and distance from the corner are all meticulously documented in the official survey field notes.
How Surveyors Select and Mark Witness Trees
The selection of a bearing tree is a deliberate process focused on durability, longevity, and resistance to decay. Surveyors generally preferred non-resinous conifers, such as cedar and yew, because their wood is highly resistant to rot and insect damage. Resinous conifers, including various types of pine and fir, were the next most favored due to their hardiness and relatively long life spans. Deciduous hardwoods were generally considered the least desirable unless species like white oak or live oak were available.
Once a suitable tree is chosen, it is permanently marked with a process involving two steps: blazing and scribing. The blazing involves removing a section of the bark and a small amount of wood on the side of the trunk facing the corner monument, creating a flat, visible area called a blaze. This large blaze is then inscribed with specific alphanumeric notations using a specialized iron tool. The scribed markings typically identify the location, such as the township, range, and section number, or simply “1/4 S.” at quarter-section corners. A second, smaller blaze is often made near the base of the tree with the letters “B.T.” to clearly identify it as a bearing tree.
Modern Importance for Property Boundaries
Bearing trees, even those established over a hundred years ago, remain a crucial legal element in modern land ownership and resurveying projects. The original survey notes detailing the tree’s species, size, bearing, and distance constitute unimpeachable evidence in boundary disputes. A modern surveyor must attempt to find the original bearing tree before establishing a new corner location. Often, the original tree may have died, but the decayed stump or an irregular scar in the ground can still provide sufficient evidence.
In some cases, the physical blaze mark, though long grown over by the tree’s subsequent layers of wood, can be located and verified. This process, known as reverse scribing, involves peeling away the bark and wood layers to reveal the original scribing, linking the current tree to the historical record. If the original monument is missing or disturbed, the recovered bearing tree, or the evidence of multiple bearing trees, is used to legally re-establish the precise location of the corner. The position determined by these historical references takes precedence over newer, less-documented methods, ensuring that current property lines are traced back to the original government surveys.