Geologic Tour of New Mexico — Physiographic Provinces

Caballo Lake State Park is located approximately 14 miles south of the town of Truth or Consequences. Caballo Reservoir is on the Rio Grande in south-central New Mexico east of Interstate 25 between Socorro and Las Cruces.

Camping, picnicing, and boating facilities are available at this state park. Caballo Lake State Park is the third largest state park in New Mexico. This park is generally quiet compared to Elephant Butte State Park to the north.

City of Rocks State Park is truly a geologic monument; it is formed by large sculptured rock columns (pinnacles) or boulders rising as high as 40 ft and separated by paths or lanes resembling city streets. About 34.9 million years ago a large volcano erupted, forming the rocks in an instant (geologically speaking); then erosion over millions of years slowly formed the sculptured columns that now provide a natural playground for children and adults alike. City of Rocks State Park was established in May 1952 to preserve this geologic wonder.

Bandelier National Monument, best known for its cultural significance and well-preserved cliff dwellings, also offers visitors a chance to observe the volcanic geology that made the area so well-suited for prehistoric Puebloan civilization. The rock in most of the monument is Bandelier Tuff, a light-colored, soft volcanic rock that formed during two very large, explosive volcanic events that occurred 1.6 and 1.2 million years ago. These two large eruptions, which together produced hundreds of cubic miles of rock, created the thick sheets of white-to-pink volcanic ash and ignimbrite seen in cliffs in many parts of the Jemez Mountains. This rock, composed of pumice, ash, and volcanic crystals, is not very strongly cemented, and, in many places, has a chalky texture. The soft and easily eroded nature of this rock allowed the deep Frijoles Canyon to be incised by Frijoles Creek, and then provided the perfect setting for the prehistoric Puebloan civilization. These people carved cliff dwellings and building blocks for structures from the volcanic rocks. They occupied this idyllic setting until around A.D. 1,100, when climate change or a combination of factors forced them to abandon the dwellings, the remains of which we see today.

The Bitter Lake National Wildlife Refuge covers about 38 square miles in central Chaves County, east and northeast of Roswell. Situated on the Pecos River where the Chihuahuan Desert meets the Great Plains, the refuge supports an amazing diversity of flora and fauna, including numerous migratory waterfowl in the winter months. Established in 1937, the refuge includes the new Joseph R. Skeen Visitor Center, which sits on the Orchard Park terrace overlooking floodplain wetlands and the redbed escarpment on the eastern skyline.

Beginning at the Visitor Center are a bike trail, a short walking trail, and an 8-mile auto-tour loop. The loop traverses a Pecos Valley terrace overlooking the floodplain for the first 4 miles. The remainder explores floodplain environments, from an abandoned Pecos River meander oxbow lake to the low-lying wetlands. The more adventuresome visitors can explore the refuge’s north tract, which includes the Salt Creek Wilderness. Here, one can hike to the mouth of Salt Creek at the Pecos River and continue onto some of the refuge’s many sinkholes, including the scenic Ink Pot.

Aztec Ruins National Monument was established in 1923 to preserve the remarkable remains of an ancestral Puebloan farming community, including a twelfth-century Chacoan great house. The settlement flourished from A.D. 1050–1150, at which time it was one of the largest Puebloan settlements in the Southwest, strategically situated between Mesa Verde to the north and Chaco Canyon to the south. Culturally it is considered a Chacoan outlier, at the northern terminus of one of the prehistoric roads that emanated from Chaco. Later occupants (in the 1200s) are thought to have had closer ties to Mesa Verde.

One of the earliest written eyewitness accounts of Aztec Ruins was provided by geologist John Newberry in 1859, who reported at that time that the walls stood 25 feet high. Both the ruins and the setting are spectacular, but the park is perhaps best known for the reconstructed Great Kiva, which was excavated in 1921 and reconstructed by Earl Morris in the 1930s. It is the only restored great kiva in the Southwest and is accessible to visitors; stepping inside provides a unique glimpse of what these ceremonial structures might have been like when they were intact. The park is now a World Heritage Site.

Manzano Mountains State Park, established in 1973, is located eighteen miles northwest of the town of Mountainair and is south of the village of Manzano in the foothills of the Manzano Mountains. “Manzano” is Spanish for apple and refers to old apple orchards found in the town of Manzano. The apple trees were planted after 1800 as determined by tree ring growth, although local legends claim that the apple trees were planted in the 17th century by Spanish missionaries traveling to the nearby Indian pueblos. The few remaining trees are probably the oldest apple trees in the United States. There are no apple trees at Manzano Mountains State Park, but Gambel oak, Emory oak, piñon, ponderosa pine, and alligator juniper trees are abundant. The alligator juniper is named for the checkered pattern on the bark of older trees, which resembles an alligator's hide. Nearby, Tajique, Torreon, and 4th of July Canyons in the Manzano Mountains contain some of the largest stands of Rocky Mountain and big-toothed maple trees in the Southwest; spectacular fall colors attract visitors from throughout the area. The Manzano Mountains also play an important role as a raptor flyway during spring and fall migrations. Some species of birds may fly 200 miles in a day and several thousand miles in a season. The park has a field checklist available to visitors who enjoy bird watching.

Smokey Bear Historical Park is in the center of the town of Capitan. In May 1950, a raging forest fire blackened approximately 17,000 acres of the Capitan Mountains in the Lincoln National Forest in central New Mexico. As forest fire fighters brought the blaze under control, a small black bear cub was found clinging to the remains of a charred tree. First aid was administered to the badly burned bear cub and he was sent to Santa Fe for further treatment. Although the fire fighters didn’t realize it then, a national symbol had been born. The story of the bear cub was told in newspapers and on radio throughout the country. The cub, named Smokey Bear, went to the National Zoo in Washington, D. C. and became the living symbol for fire prevention. Through many successful campaigns, Smokey not only was responsible for reducing the number of man-made forest fires but he also raised more than $27 billion through donations in the past 40 years.

Conchas Lake State Park was established in 1955 and named after the Conchas River, one of the tributaries of the Canadian River. It is 24 mi north of Newkirk and 31 mi northwest of Tucumcari on NM–104 and NM–129. Conchas is Spanish for shells and was applied to a group of Indians living in the area when Spanish explorers arrived in the 17th century. The word conchas may be a corrupted name that is confused with the Spanish word conchos, a term also used to describe the Native American tribes in northern New Mexico.

The dam that formed Conchas Lake was the 17th dam in the country built by the U.S. Army Corp of Engineers. One of the state’s oldest dams, it was completed in 1939 to control floods, store water for irrigation and local supplies, and assist in local economic recovery from the Depression.

Petroglyph National Monument is located on Ceja Mesa on the west side of Albuquerque. The monument is best known for the estimated 25,000 rock art images carved into basalt erupted from the approximately 200,000-year-old Albuquerque volcanic field. Using stone chisels and hammer stones, the ancestors of the Puebloan Indians cut most of the petroglyphs into the desert varnish coating the basalt between 1300 and 1680 A.D. A few of the markings are much older, dating back to perhaps 2000 B.C. Spaniards and later generations of Albuquerque inhabitants have produced younger petroglyphs with more modern themes. The monument, created in 1990, includes about 17 miles of petroglyph-covered basalt cliffs and five extinct volcanoes.

West of the flocks of birds and birdwatchers along the wetlands of the Rio Grande, a story of cataclysmic volcanic eruptions, ancient dune fields, and long-gone towering mountains lie quietly awaiting visitors to the Bosque del Apache National Wildlife Refuge. The Chupadera Wilderness Trail and the Canyon Trail traverse this geologic record in the contemplative solitude of a wilderness setting, affording “rockwatchers” a quick trip through millions of years of Earth history.