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• The Late Cretaceous-age Mesaverde Group sandstones and coal-bearing rocks aze the bedrock of the study area and are part of the Uintah Field, one of three major coal fields in the region. This group can be subdivided into two subgroupings, one coal-beazing and the other noncoal-beazing. The coal-beazing part includes the Staz Point, Blackhawk, Neslen, Mt Gazfield, Iles, and Williams Fork Formations. This area was once a lowland swamp that resembled present-day environments like the Mississippi delta, the Louisiana coastal plains, lagoons and swamps, and the Everglades. One of the characteristics of this part is its abundant beds of carboniferous shale and coal produced from the vegetation of the great swamps, which included a mixture of ferns, gymnosperms, and angiosperms. These plants were eaten by dinosaurs, and these kinds of formations have produced skeletal-rich deposits in many azeas of the world. However, acid conditions of the waters that seeped through the plant-rich sediments often destroyed the remains of the animals that lived in the swamps and transitional environments (Young 1987:47). It is best known for fossils of the duckbill (hadrosaurs) and horned (ceratopsians) dinosaurs. In North America, the Two Medicine Formation of Montana, the Judith River Formations of Alberta, and the Lance Formation of Wyoming have produced many of these fossils. In contrast, the Mesaverde deposits of the Colorado, Utah, and Wyoming region, aze almost devoid of skeletal remains, but aze known to contain abundant tracks (ichnofossils), predominately those of the large hadrosaurs. The tracks of the homed dinosaurs are rare and poorly known, although they aze as common in the skeletal record as the hadrosaurs. Paleontologists speculate that this marked difference suggests that the ceratopsians may have avoided the environments frequented by the hadrosaurs (Lockley 1991:100). In west central Colorado, the most common vertebrate fossils of the Mesaverde are those found on the tops of coal beds. In a study of the Grand Junction Resource Area, Armstrong and Kihm reported finds offish, turtle scutes, crocodile scutes and bones, and innumerable dinosaur tracks in the Book Cliffs north of Grand Junction (Armstrong and Kihm, 1980). The most unusual find in the formation is a nest of dinosaur eggs of an unidentified type that was reported from the Roadside Mine at Cameo, north of Palisade. In the Paonia--Somerset azea, Hazley Armstrong (BLM State Paleontologist) reports that the local coal mines had produced several important fords despite the lack of a "Class I" rating for the Mesaverde in that area. Recovery of plant fossils have been made from the Red Canyon Mine, and the Cypress-Orchazd Valley Mine has yielded two coalified conifer stumps. Leaves and plant fossils have also been found in a road cut near the Paonia Reservoir, and a paten frond (Sabalites sp.) was found in the rip-rap below the dam. The Cypress-Orchard Valley Mine has also produced many inoceramid clams and other invertebrates, as well as a hadrosaur dinosaur tibia and femur. Hadrosaur and theropod tracks have been recovered from the States-Hall Mine (Armstrong, personal communication August 2000).