What is "arborglyph"

Arborglyphs, dendroglyphs, silvaglyphs, modified cultural trees, or aspen carvings are tree carvings made in the bark of aspen trees by shepherds, many of them Basque and Irish American, throughout the Western United States. They have been documented across northern California and in areas such as Boise, Idaho and Steamboat Springs, Colorado.

A project run by the USDA Forest Service in 1997 to record and study arborglyphs in the Fremont National Forest of Oregon is documented here.

Researchers in Boise, Idaho have also reportedly documented arborglyphs in their area.

In the West the preferred carving tree is the aspen, which has a lifespan of only about 85 years on average.