Pueblo Foothills Research Natural Area Burns District , BLM Northern Basin and Range Ecoregion Cell(s): Shadscale-spiny hopsage-green mormon tea salt desert scrub Mormon tea/narrowleaf cottonwood riparian area

Access by unpaved roads.

Situated south of Fields in Harney County, Oregon, the 1019 ha Pueblo Foothills RNA protects an ecosystem recognized by the ONHP as the best example of a narrowleaf cottonwood (Populus angustifolia)/mormon tea (Ephedra viridis, E. nevadensis) community complex in the Basin and Range Physiographic Province. Another important plant community is shadscale (Atriplex canescens)/spiny hopsage (Grayia spinosa)/bud sage (Artemisia spinescens). Annual precipitation averages 18 cm. Soil series represented are Felcher (south), Skedaddle (south, north), Pernty (north), Sagehen, McConnel, Outerkirk and Defenbaugh, with rock outcrops. Elevation ranges from 1300 to 1700 m. Special Status plant species that also occur in this unique ecosystem include narrowleaf cottonwood, large-flowered chaenactis (Chaenactis macrantha), naked stemmed phacelia (Phacelia gymnoclada), ochre buckwheat (Eriogonum ochrocephalum ssp. calcareum), and Malheur cryptantha (Cryptantha propria). The only human development is a small piece of the Arizona Creek Road; two other roads within the area have been blocked and rehabilitated. Disturbances include livestock grazing and some erosion along streambanks. The RNA has a high potential for the occurrence of epithermal-related gold, silver, or mercury deposits; part of the area has a high potential for porphyry related deposits of gold, copper, or molybdenum, and a moderate potential for the occurrence of low sulfide gold deposits. Historically, the area was heavily claimed for locatable minerals, but only a few claims remain at the present time. The BLM has established transects for monitoring Populus angustifolia and Ephedra nevadensis.