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
Black Rock Mountain State Park Black Rock Mountain State Park Black Rock Mountain State Park is a Georgia state park west of Mountain City in Rabun County, Georgia, in Georgia's Blue Ridge Mountains. It is named after its sheer cliffs of dark-colored biotite gneiss. Astride the Eastern Continental Divide at an elevation of , the park provides many scenic overlooks and vistas of the southern Appalachian Mountains. On a clear day, four states are visible: Georgia, North Carolina, South Carolina, and Tennessee. In addition to Black Rock Mountain itself, the park includes four other peaks over in elevation, making it the highest state park in