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
Hole in the Rock (rock formation) expedition, runs southeast from near the town of Escalante to a parking area just above the crevice. Alternatively, the bottom of the route can be accessed by boat, at buoy 66 on Lake Powell in the Glen Canyon National Recreation Area. The Hole in the Rock was listed on the National Register of Historic Places in 1975. Hole in the Rock (rock formation) Hole in the Rock is a narrow and steep crevice in the western rim of Glen Canyon, in southern Utah in the western United States. Together with another canyon on the eastern side of the Colorado River,