Nature

The rocks of John Day Fossil Beds are mostly volcanic in origin, including the blue-green claystones of Blue Basin.

NPS Photo

John Day Fossil Beds National Monument protects one of the longest and most continuous records of evolutionary change and biotic relationships in North America.

Here, scientists have unearthed fossils of land plants and animals dating back from 44 million to 5 million years old, as well as evidence of dramatic climatic changes.

The monument includes over 14,000 acres found in 3 widely separated units, the Sheep Rock Unit, Painted Hills Unit, and Clarno Unit. All 3 units are in the John Day River Basin. The John Day River is the longest undammed tributary into the Columbia River.

Deep ravines eroding fossil-bearing formations bisect the steep mountainous terrain. Elevations range from 2,000 to 4,500 feet within the John Day Fossil Beds. The monument lies within the Blue Mountain physiographic province in northeast Oregon. With average rainfall ranging from 9-16 inches, it is categorized as a semi-arid climate. Much of the precipitation for the area falls in the winter.

The river and streams are vital to the survival of many of the wildlife species inhabiting the monument. Over 50 species of birds, 40 species of mammals, 14 species of reptiles, 6 species of amphibians, and 10 species of fish inhabit the monument. Over 240 plants and flowers have adapted to the growing conditions found here.

Two Research Natural Areas are located in the Sheep Rock Unit and protect nearly pristine vegetative communities. Seventy-five acres of agricultural land is irrigated and maintained to preserve the cultural landscape of the Cant Ranch National Historic District.