The Coweeta Basin comprises 2,185 hectares within the Blue Ridge geologic province in North Carolina, and is administrated by the USDA Forest Service. The laboratory has been dedicated to forest hydrology research since its establishment in 1933. Elevations range from 679 to 1,592 meters. More than fifty kilometers of streams drain the area. Regional Climate The regional climate is classified as marine with cool summers, mild winters, and adequate rainfall during all seasons. Mean annual temperature is 13 C. Annual precipitation is high and variable over the area, with an average of 178 cm at lower elevations to over 250 cm on upper slopes. Snow typically contributes less than 2 percent to total precipitation. Coweeta is the first major mountain range contacted by air masses moving over the industrialized Piedmont region to the south. Analyses of precipitation chemistry have shown the influence of both local and regional activities on nutrient inputs to forest ecosystems. The annual pattern of stream flow is similar to precipitation, and perennial flow occurs for watersheds as small as 6 ha. Streams are high-gradient with dense rhododendron cover, and woody debris is an important structural feature. We have recognized four major patch types in streams: (1) cobble riffles, (2) rock outcrops, (3) pools, and (4) debris dams. Structural and functional attributes of these patches differ. Regional Geology Geologically, this region has undergone great uplift, repeated and complex folding and erosion. The soils at Coweeta are classified as either immature Inceptisol or older developed Ultisols. Soil physical and chemical properties vary substantially over the basin. Soils are relatively high in organic matter and moderately acid with both low cation exchange capacity and percent base saturation, characteristics which are typical for highly watered Ultisols. Forest Types Deciduous oak species are the dominant canopy species in Coweeta forests with an abundant evergreen under-story component comprised of Rhododendron maximum and mountain laurel (Kalmia latifolia). Four major forest types are recognized: (1) northern hardwoods, (2) cove hardwoods, (3) oak (-chestnut), and (4) oak-pine. Treatments Since Coweeta was established, thirty-two weirs have been installed on streams.  Seventeen of these weirs are currently operational. Stream gauging was initiated on most watersheds between 1934 and 1938, and stream chemistry measurements date back to 1968. Research has been conducted on eight mixed hardwood control areas and 13 catchments where forest management prescriptions have been applied. Past treatments include varying intensities of cutting, ranging from light selection through clear-cutting; conversion of hardwoods to grass and subsequent succession to hardwoods; multiple-use management; mountain farming; and the application of herbicides and fertilizers.