Geologic Tour of New Mexico — Physiographic Provinces

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.

Gila Cliff Dwellings National Monument is in the Mogollon Mountains approximately 44 miles north of Silver City, New Mexico. Gila Cliff Dwellings National Monument was established in 1907 and is one of the nation’s oldest monuments. The monument lies within the Mogollon-Datil volcanic field; volcanic eruptions from this field covered 40,000 km2 of southwestern New Mexico and southeastern Arizona with lava and ash flow tuffs 40 to 24 million years ago.

The Carrizozo Malpais are one of the youngest volcanic features in the state of New Mexico. The Malpais, which are the 75 km-long black feature in the satellite image, are basaltic lava flows, such as are being erupted today in Hawaii. State highway 380 traverses the Carrizozo Malpais, and this road provides good access to people who want to view, or visit the lava flows. The Valley of Fires Recreation Area is located on the Carrizozo Malpais.

This recreation area in the Lincoln National Forest has spectacular cliffs and features a year-round spring-fed stream, waterfalls (the largest of which has a 150-foot drop), and many refreshing clear-water wading pools. There are picnic areas and several hiking trails, including T–68 and T–68A that lead to the spring source of the waterfalls. The Apache name for the area was “gostahanagunti,” which means hidden gulch, and the presence of flakes of worked chert, grinding holes (bedrock mortars), and nearby pictographs testify to long-standing Native American use of this wildlife-rich oasis in the desert.

Ute Lake State Park was established in 1964 at a cost of approximately $5 million and was named after Ute Creek, one of the tributaries of the Canadian River that is impounded by a dam. The small town of Logan is on the east side of the lake, and the lake extends upstream in both the Ute and Canadian Rivers. It is 25 miles northeast of Tucumcari on US–54, NM–39, and NM–540 and is approximately 20 miles west of the Texas–New Mexico state line. Most of the land surrounding Ute Lake is private. All the water is open to the public. The park is in the Pecos Valley section of the Great Plains physiographic province. It lies on the north edge of the Llano Estacado or “staked plains.”

Leasburg Dam State Park is adjacent to Fort Selden State Monument on NM–157 (Fort Selden Road) at the Radium Springs exit on I–25, north of Las Cruces. It is an area rich in both geologic and human history. The location was an ancient Indian campground and a crossing point for Spanish caravans headed across the Jornada del Muerto. Living-history demonstrations of 19th century military life at Fort Selden highlight many weekends during the summer. Wildlife viewing, especially bird watching, is popular at the state park. A bird list is available from the park office. In the winter months many species of ducks, teals, snow geese, cranes, herons, egrets, swans, and pelicans migrate through the southern Rio Grande valley and can be seen at the state park. Numerous raptors, including owls, turkey vultures, eagles, and hawks, can be seen hunting in the area. Small mammals common to the park include rabbits, squirrels, chipmunks, rodents, coyotes, and foxes.

Ghost Ranch is located approximately 38 miles northwest of the town of Española, New Mexico, just north of U.S. Highway 84, and is run by the Presbyterian Church as a conference center. It has facilities for lodging and camping, as well as paleontology and cultural museums. It lies in the Chama Basin, a broad shallow basin along the eastern margin of the Colorado Plateau in the transition between the Plateau and the Rio Grande rift.

The craggy gray granodiorite spire of Cookes Peak, the highest point in the Cookes Range at 8,404 feet, is a prominent landmark in southwestern New Mexico. Cookes Spring on the southeast side of the range is one of just a few perennial springs in this part of New Mexico; consequently, this peak was an important marker of water for Native American, Spanish, and American travelers through the region during the 19th century. The peak was named for Captain Phillip St. George Cooke, who led the Mormon Battalion through southern New Mexico during the winter of 1846 while scouting an overland wagon route for the U.S. Army. Later, a Pony Express mail station was established near the spring. Fort Cummings was built nearby in 1863 to protect travelers from Apache attacks; the fort was manned by the U.S. Army off and on until Geronimo surrendered in 1886. Ruins of the Cookes Spring Station of the Butterfield Trail and Fort Cummings are located about a mile south of the present-day Hyatt Ranch.

Sevilleta National Wildlife Refuge (NWR) is located in central New Mexico about 15 miles north of Socorro. The refuge spans the Rio Grande valley from the Sierra Ladrones on the west to the Los Pinos Mountains on the east, an area of approximately 30 miles by 15 miles, encompassing 230,000 acres. The area was designated a Spanish land grant, Sevilleta de la Joya, in 1819. The land grant was sold in 1928 to Socorro County and then, in 1936, to General Thomas D. Campbell, under whom it became a ranch for sheep and cattle. The Campbell Family Foundation donated the land to the Nature Conservancy in 1973, which then passed it on to the U.S. Fish & Wildlife Service to become a national wildlife refuge dedicated to preservation and enhancement of the integrity and natural character of the land. The transfer stipulated that the land should undergo natural processes of succession, including floods and fires, without human interference. Thus, most of the refuge has very limited public access, but the Mesa View Trail west of the Visitor Center is open for hiking at least five days per week.

Percha Dam and Caballo Lake State Parks, located south of the town of Truth or Consequences, offer striking views of the Caballo Mountains and Red Hills, prominent uplifts in the southern Rio Grande rift. The Percha and Caballo dams were built for the Bureau of Reclamation’s Rio Grande Project in 1918 and 1936–38, respectively. Percha Dam, although only 18.5 feet tall, diverts water into the Rincon Valley, irrigating farmland where much of New Mexico’s famous green chile is grown, along with many other crops. Two miles upstream, the 96-foot-tall and 4,590-feet-wide earth-fill Caballo Dam stores water released from hydroelectric- power generation at Elephant Butte Dam and regulates delivery of that water to downstream users during irrigation season.