SANTA ELENA CANYON—The majestic grandeur of the Big Bend area is emphasized by the towering walls of the Santa Elena Canyon. Here, where the Rio Grande emerges from the winding gorge, Mexico appears at the left, the United States on the right.
Here, a deep gash in the mesa de Anguila and Sierra Ponce marks the course of the river for eighteen miles. Through millions of years, the silt and gravel laden waters have continued their endless task of grinding away the limestone bit by bit until now the walls of the canyon rise perpendicularly more than fifteen hundred feet above the waters of the river.
BOQUILLAS, MEXICO AND SIERRA DEL CARMEN RANGE—The Village of Boquillas is located in a picturesque setting along the Rio Grande and at the base of the Sierra del Carmen Range.
SIERRA DEL CARMEN RANGE—One of the outstanding scenic features of the eastern section of Big Bend National Park is Mexico’s picturesque Sierra del Carmen Range, which exceeds 8,000 feet in elevation.
SPIRES AND PINNACLES IN THE GRAPEVINE HILLS—Erosion, like a master sculptor, has carved many weird and grotesque forms throughout the Big Bend area.
The geological story of Big Bend is vividly revealed in the rock strata, the spires, buttresses, erosive remnants, arroyos and canyons. The entire Big Bend area was submerged by an ocean millions of years ago. Sediments of sand, mud and lime deposited on the floor of the sea later hardened into rock. Common to all oceans, various types of aquatic life abounded in these waters, many of which were fossilized in the forming of the rock. Igneous action within the earth’s interior caused an uplifting of the surface and receding of the ocean waters. It was during this period that giant trees grew and later became petrified. (Evidence may be noted on the Tornillo Flats.) Swamp and shoreline vegetation provided food for the dinosaurs during this period. As the igneous action increased, molten rock was deposited in some sections and mountains were formed along the lines of greatest pressure. This newly formed rock was soft and highly susceptible to the processes of erosion, which gradually broke down the softer portions of the mountains, making deposits in the valleys and lowlands.
