Laserfiche WebLink
Twentymile Park are capped by the thick, light colored Twentymile sandstone. Outcroppings of the <br />Twentymile sandstone in the area are the frequent locations of rock art panels and rockshelters (Pool <br />1997). Although sandstone outcrops in the project area, no cliff faces suitable for rockshelters or <br />rock art occur. <br />The area contains an abundance of diverse flora and fauna. Flora in the area varies by <br />elevation and topographic context. Stands of aspen trees and thick shrubs are found at the higher <br />elevations on north facing slopes while sagebrush, grasses, and mixed forbs are found in the parks <br />and along drainages at the lower elevations and on south facing slopes. Vegetation cover in the <br />project APE averaged approximately 20-40%. Much of the inventoried area is improved range <br />where the native sagebrushbrushbrush has been replaced by a mix of native and non-native cattle <br />forage, although the native sagebrushbrushbrush community is coming back in some areas. In <br />addition, there are many areas that were cultivated during the mid-20th century. Evidence for tillage <br />can be seen in some parts of the current APE. Area fauna includes a variety of large ungulates, <br />black bear, coyote, fox, and several species of small and medium-sized mammals. Numerous avian <br />species also inhabit or utilize the area. <br />At present, the area is used predominantly for ranching, agriculture, and coal mining. Large <br />portions of the parks and valleys appear to have been mowed and/or plowed in the past and cattle <br />grazing is ongoing. The project area is rich in natural resources that would have been attractive to <br />the Native American inhabitants during prehistory. <br />CULTURE HISTORY AND PREVIOUS WORK <br />Prehistoric Overview <br />A variety of site types are present in the general project area, representing most of the <br />thematic contexts outlined in the original RP3 documents for Northwest Colorado (Grady 1984; <br />Mehls 1984) and in the more recent prehistoric contexts for the area by LaPoint (1987), Reed and <br />Metcalf (1999) and McDonald and Metcalf (2006). Prehistoric sites in the area include lithic <br />scatters, open campsites, quarry sites, rockshelters, and rock art panels. Evidence of Paleoindian <br />inhabitants in the area consists of a few isolated projectile points including Cody Complex points <br />at 5RT139. Archaic-age lithic scatters and open camps have been recorded in the area as well as <br />some rock art panels believed to be Archaic in age. Excavations at the Red Army Rockshelter <br />(5RT345) located a few miles to the south recovered evidence of multiple occupations spanning the <br />Pioneer Archaic through Protohistoric, including two house structures within the shelter (Pool 1997). <br />Numerous Formative Era Aspen Tradition age lithic scatters and open camps have also been <br />recorded in the general area, as have Protohistoric and Historic Ute or Shoshone rock art sites. <br />In the Northern Colorado River Basin, the prehistoric sequence has been divided into four <br />broad eras, each of which is further divided into time periods, traditions, or phases (Reed and <br />Metcalf 1999). The eras are Paleoindian, Archaic, Formative, and Protohistoric (Table 1). <br />The chronological sequence is built around a variety of cultural traits but, as noted by Reed <br />and Metcalf (1999:71), no single defining characteristic satisfactorily separates one period from <br />another. Rather, periods and, phases are overlain on a series of traits that have continuity through