Geologic map of the North Fork of the American River Wilderness Study Area and adjacent parts of the Sierra Nevada, California

1980 ◽  
Keyword(s):  
Sierra Nevada ◽  
The North ◽  
American River ◽  
North Fork ◽  
Geologic Map

scholarly journals Intercomparison of Meteorological Forcing Data from Empirical and Mesoscale Model Sources in the North Fork American River Basin in Northern Sierra Nevada, California*

2013 ◽  
Vol 14 (3) ◽  
pp. 677-699 ◽  
Author(s):  
Nicholas E. Wayand ◽  
Alan F. Hamlet ◽  
Mimi Hughes ◽  
Shara I. Feld ◽  
Jessica D. Lundquist
Keyword(s):  
River Basin ◽  
Sierra Nevada ◽  
Mesoscale Model ◽  
Wrf Model ◽  
High Elevation ◽  
Meteorological Forcing ◽  
The North ◽  
Single Station ◽  
American River ◽  
North Fork

Abstract The data required to drive distributed hydrological models are significantly limited within mountainous terrain because of a scarcity of observations. This study evaluated three common configurations of forcing data: 1) one low-elevation station, combined with empirical techniques; 2) gridded output from the Weather Research and Forecasting Model (WRF); and 3) a combination of the two. Each configuration was evaluated within the heavily instrumented North Fork American River basin in California during October–June 2000–10. Simulations of streamflow and snowpack using the Distributed Hydrology Soil and Vegetation Model (DHSVM) highlighted precipitation and radiation as variables whose sources resulted in significant differences. The best source of precipitation data varied between years. On average, the WRF performed as well as the single station distributed using the Parameter Regression on Independent Slopes Model (PRISM). The average percent biases in simulated streamflow were 3% and 1%, for configurations 1 and 2, respectively, even though precipitation compared directly with gauge measurements was biased high by 6% and 17%, suggesting that gauge undercatch may explain part of the bias. Simulations of snowpack using empirically estimated longwave irradiance resulted in melt rates lower than those observed at high-elevation sites, while at lower elevations the same forcing caused significant midwinter melt that was not observed. These results highlight the complexity of how forcing data sources impact hydrology over different areas (high- versus low-elevation snow) and different time periods. Overall, results support the use of output from the WRF model over empirical techniques in regions with limited station data.

Evidence for a Prehistoric Petroglyph Trail Map in the Sierra Nevada

1988 ◽  
Vol 9 (2) ◽  
pp. 147-154 ◽  
Author(s):  
Willis A. Gortner
Keyword(s):  
Sierra Nevada ◽  
Topographic Map ◽  
North Central ◽  
The North ◽  
Map Interpretation ◽  
American River ◽  
North Fork

A single petroglyph site in the North-Central Sierra Nevada in the upper watershed of the North Fork of the American River has a unique glyph with meandering and connecting wavy lines that are now proposed as trail maps. A tracing of this glyph was made from a photograph, and this was then placed with the same compass alignment on a topographic map showing all petrographic sites along the North Fork watershed. The ability to superimpose and accurately orient the glyph tracing over a map of these petroglyph sites, and the presence of petroglyphs on seventy-seven individual rock outcroppings mostly within 50 m of the presumed trails, support the trail map interpretation of this rock carving. It is suggested that a hunt shaman may have incised this glyph for ritualistic use.

Projectile Point Typology and Chronology in the North Central Sierra Nevada

2002 ◽  
Vol 23 (2) ◽  
pp. 157-183
Author(s):  
Jeffrey S. Rosenthal
Keyword(s):  
Sierra Nevada ◽  
Full Range ◽  
Morphological Variability ◽  
Western Slope ◽  
Projectile Point ◽  
Projectile Points ◽  
The North ◽  
Large Numbers ◽  
American River ◽  
Point Types

Despite years of concerted research, no well substantiated projectile point chronology for the western slope of the central Sierra Nevada has been established. Several reasons for this have been identified, including a lack of datable contexts, stratigraphic mixing, and excessive morphological variability resulting from material constraints and regular tool resharpening. Existing projectile point typologies, while accommodating the full range of morphological variation, have proven cumbersome due to large numbers of distinct types and sub-types. Further, chronological control has relied on inferences drawn from other regions, with little local support for inferred point sequences. To address these problems, the following study employs a large assemblage of projectile points from three stratified archaeological sites in the American River watershed. Projectile points are segregated using two common measurements—neck width and proximal shoulder angle. The newly defined types are then compared to regional stratigraphic patterns, revealing a consistent sequence of dart and arrow point types spanning the middle through late Holocene.

Sign in / Sign up

Export Citation Format

Share Document