Brazos Mountains to 55 million years ago during the Laramide orogeny. To the east and northeast lie the Sangre de Cristo Mountains which share a similar geological history. The Brazos Cliffs, which form a dramatic backdrop to Tierra Amarilla, are formed of Precambrian quartzite. Brazos Mountains The Brazos Mountains is a range in far northern Rio Arriba County, in northern New Mexico in the southwestern United States. A high crest runs from the border with Colorado for over in a south-southeasterly direction. The high point of the range at is on Grouse Mesa, at the Brazos Benchmark. Two miles (3 km) to
Uhangri Formation Uhangri Formation The Uhangri Formation, located at the Uhangri Dinosaur Fossil Site, is a geological formation from which fossil pterosaur tracks have been recovered near Haenam-eup, Jeollanam-do, South Korea. The Uhangri Dinosaur Fossil Site area was originally covered by ocean, uncovered when Lake Damsuho, and surrounding area, was created by the construction of the Geumho Tide project. Lake Damsuho has cliffs that are 3–4 meters/10–13 feet high, stretching about 5 kilometers/3.1 miles, made up of sedimentary rock formed during the Cretaceous age. Embedded in the rock formations around the lake are fossilized footprints of dinosaurs, pterosaurs and water birds that