Archaeological Report
Harney County Oregon, Range Seeding Projects

The Drewsey Resource Area includes parts of three physiographic provinces: the Owyhee Uplands to the east, High Lava Plains in the west and central portions, and the Basin and Range province on the south. A fourth physiographic province, the Blue Mountains, borders the area on the north.

Geologically, the High Lava Plains are a comparatively recent feature, consisting primarily of lava and ashflows, Pliocene to Pleistocene in age, though volcanic activity has continued to some extent through much of the Holocene. This volcanic activity has resulted in numerous basalt, ignimbrite, obsidian and various crypto-crystalline silicate formations that have been used as source materials for lithic tool manufacture. Older formations in the Basin and Range province provide sources of chert, including silicified wood, agate and chalcedony.

The climate of this area is characterized by extremes in temperature with bitterly cold winters, hot summer days and broad daily temperature fluctuations. Precipitation is variable: generally sparse in the lowlands and slightly higher in the uplands, and varying from about eight inches per year in some areas to 20 inches per year in others. Winds are usually from the west and tend to be gusty with occasional strong winds not uncommon. The nature and degree of climatic fluctuations through the prehistoric period is a matter of debate. Generally, it can be assumed that the climate has not changed drastically since the end of the Pleistocene, although minor variance over extended periods has been sufficient to greatly alter the local environment.

Currently the region includes four of the five major vegetative zones described by Hansen (1947): 1) The Desert Shrub Zone, 2) The Big Sage Zone, 3) The juniper Zone, and 4) The Quaking Aspen Zone. Sagebrush seems to be a major constituent of all of these zones and is undoubtedly the most characteristic vegetation of the region. Recent palynological studies in a nearby area (Aikens et. al., 1979) indicate that there have been irregular and substantial fluctuations in the preponderance of sagebrush species through the years. This variation has been nearly mirrored by changes in the proportion of conifer species, with the conifers increasing as sagebrush declined and visa-versa. These variations probably reflect minor fluctuations in climatic conditions, especially precipitation, which presumably affected fauna as well as flora, and undoubtedly influenced the human inhabitants of the region.

Today, much of southeastern Oregon is devoted to cattle grazing, so the cow is the dominant herbivore under somewhat less than "natural" conditions. Deer and pronghorn antelope inhabit the area, along with numerous smaller mammal species including coyotes, foxes, bobcats, beavers, porcupines, badgers, raccoons and numerous small rodents. Snakes, lizards, birds and abundant insect species round out the terrestrial wildlife, while the amphibians include frogs and toads. Fish of various sorts are found in the lakes and streams of the area. Buffalo were present in the region during the prehistoric period but were probably never very numerous. During the late Pleistocene other large animal species were probably present, including native horses, camelids, extinct bison species and ground sloths.