Arborglyphs, dendroglyphs, silvaglyphs, modified cultural trees, or aspen carvings are tree carvings made in the bark

Bark

Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...

 of Aspen trees by Basque

Basque diaspora

The Basque diaspora is the name given to describe people of Basque origin living outside their traditional homeland on the borders between Spain and France...

 and Irish American

Irish American

Irish Americans are citizens of the United States who can trace their ancestry to Ireland. A total of 36,278,332 Americans—estimated at 11.9% of the total population—reported Irish ancestry in the 2008 American Community Survey conducted by the U.S. Census Bureau...

 shepherds throughout the Pacific Northwest

Pacific Northwest

The Pacific Northwest is a region in northwestern North America, bounded by the Pacific Ocean to the west and, loosely, by the Rocky Mountains on the east. Definitions of the region vary and there is no commonly agreed upon boundary, even among Pacific Northwesterners. A common concept of the...

 and Western United States

Western United States

.The Western United States, commonly referred to as the American West or simply "the West," traditionally refers to the region comprising the westernmost states of the United States. Because the U.S. expanded westward after its founding, the meaning of the West has evolved over time...

. They have been documented across northern California

Northern California

Northern California is the northern portion of the U.S. state of California. The San Francisco Bay Area , and Sacramento as well as its metropolitan area are the main population centers...

 and in areas like Boise, Idaho

Boise, Idaho

Boise is the capital and most populous city of the U.S. state of Idaho, as well as the county seat of Ada County. Located on the Boise River, it anchors the Boise City-Nampa metropolitan area and is the largest city between Salt Lake City, Utah and Portland, Oregon.As of the 2010 Census Bureau,...

 and Steamboat Springs, Colorado

Steamboat Springs, Colorado

The city of Steamboat Springs is a Home Rule Municipality that is the county seat and the most populous city of Routt County, Colorado, United States. The city is also known as "Steamboat," "The Boat," or "Ski Town USA". As of the 2010 census, the city population was 12,088.The city is an...

.

A project run by the USDA Forest Service in 1997 to record and study arborglyphs in the Fremont National Forest

Fremont National Forest

The Fremont National Forest is a United States National Forest named after John C. Frémont, who explored the area for the United States Army Corps of Engineers in 1843. It is located in western Lake and eastern Klamath counties in Oregon, and has a land area of . There are local ranger district...

of Oregon is documented here

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

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