Text Page INTRODUCTION 1 ECOLOGY 2 HISTORY OF MAN IN THE AREA 4 GEOLOGIC HISTORY 5 PALEONTOLOGY 14 Illustrations Figure 1. Geologic Map of Palo Duro Canyon 6 Figure 2. Stratigraphic Section and Geologic Time Scale 7 Figure 3. Paleogeographic Map of the Permian Period 9 Figure 4. Paleogeographic Map of the Triassic Period 11 Figure 5. Paleogeographic Map of the Pliocene Epoch 13 Figure 6. Paleogeographic Map of the Pleistocene Epoch 15 Figure 7. Life of Triassic Time 17 Figure 8. Pliocene Mammals 19 INTRODUCTION Palo Duro Canyon State Park is located 13 miles east of Canyon, Texas, on State Highway 217 and 17 miles southeast of Amarillo, Texas. The park encompasses about 15,000 acres of eastern Randall and western Armstrong counties. The initial park area was purchased by the State of Texas in 1931. In 1973 the park boundary was extended to incorporate a famous topographic structure, the Lighthouse (frontispiece). Excellent picnic and camping facilities are available within the Park. Extending away from the canyon rim is a gently undulating land surface called the Llano Estacado or Staked Plains. It is part of the High Plains, a vast piedmont plain which extends along the eastern base of the Rocky Mountains from Wyoming to Texas. The eastern edge of this plain is, in places, an abrupt escarpment (cliff) known as the caprock. Palo Duro Canyon is a westward extension of this escarpment that has been carved into the High Plains by the Prairie Dog Town Fork of the Red River. In the park area the canyon is several miles wide. The canyon rim is about 3,500 feet above sea level and the canyon floor, although highly irregular is approximately 2,700 feet above sea level. The maximum depth of the canyon is about 800 feet. The United States Geological Survey has published an excellent topographical contour map of the canyon, the Fortress Cliff Quadrangle. It can be purchased at the park or from the United States Geological Survey. The Park area normally receives about 20-30 inches of rainfall per year and has a frost free period of approximately 200-240 days per year. The yearly temperature ranges from 0-70°F in the winter and from 65 to 100°F in the summer. The weather is considered fair about 75% of the time. The nights are cool even in the summer. ECOLOGY