When my sister and brother and I were kids growing up in Red River, our interest in geology extended only to whatever bright, shiny things we could carry in our pockets. Quartz, pyrite, selenite, pretty river rocks … all came home where my dad John, the geologist, would admire our “treasures.”
There was this time, though, when one of us handed him a chunk of rock embedded with gold. “Where’d you get this?” he asked eagerly. “Dunno,” one of us answered, shrugging.
That motherlode was left to be found by other prospectors, the mystery of its origins left unsolved. We, meanwhile, grew to love Northern New Mexico’s fascinating geology — as much for its beauty than any value … real or imagined.
It’s worth your time just to drive the 86-mile Enchanted Circle loop —the highways which describe a circle around Wheeler Peak, elevation 13,161, the highest point in the state — with side trips to the Rio Grande Gorge Bridge, Wild Rivers Recreation Area, Cimarron Canyon and Coyote Creek State Park. All are packed with geological marvels.
Beginning in Taos, head out to the intersection of Highways 522, 150 and 64. Take Highway 64 8 miles to get to the Rio Grande Gorge Bridge. At 650 feet, it’s the second highest cantilever truss bridge in the United States.
This is an excellent place to view the “Rio Grande Rift,” a fault-bounded basin that extends from central Colorado through New Mexico to Mexico which led to the uplift of the Sangre de Cristo mountains. Some speculate the widening will continue until one day, millions of years from now, it becomes an inland sea or ocean basin.
Probably too soon to start buying seaside real estate, though.
From the bridge’s vantage point, you can see the huge rift between the mountains to the east and west as well as basalt left from lava flows, extinct volcanos and sedimentary layers and gravel — all evidence of violence, erosion and the passage of time.
Head back to Highway 522 and go north 20 miles to Questa.
Once in Questa, you can turn onto Highway 38, though a trip north to the Wild Rivers Recreation Area is worthwhile for its geologic interest, scenery, excellent hiking and petroglyphs that can be found in the canyon floor. Bureau of Land Management staff also offer guided interpretive hikes into the gorge. (Travel north 3 miles to Cerro, turn left on Highway 378, then its another 12 miles to Wild Rivers.)
As you enter the canyon to Red River 13 miles east, you will pass the Carson National Forest Questa Ranger District (need maps? information?) Immediately past there you will see steep cliffs which are part of the Bear Canyon pluton (an intrusion of igneous rock which solidified from molten magma from deep in the earth’s crust).
The high cliffs on the left are the Amalia Tuff — rock made of fine-grained volcanic fragments and ash which erupted from the Questa Caldera about 25 – 26 million years ago.
Just past Goat Hill Campground, you’ll pass the entrance to the molybdenum mine’s underground operation (molybdenum is used for hardening steel). A concrete tower near Goat Hill (the hill with the road around it) is the main service shaft to the mine.Heading east from Quest to Red River on NM 38,
Goat Hill Gulch opposite Goat Hill Campground is also the site of frequent flash floods and recently scientists speculated that the mine’s Goat Hill North waste rock pile could one day set off a major landslide taking out the highway and damming up the Red River. Molycorp is working to mitigate that risk.
As you head up the highway, you will pass a huge slope covered with waste from the mine’s open-pit mine operation.
Though it has had different owners, Molycorp has been in operation since 1923 beginning with underground mining. Pit mining was in operation from 1964 until 1985 when the new underground operation began. Mining operations ceased for good in 2014. In 2011, the mine and its nearby tailings facility were declared a Superfund site by the Environmental Protection Agency. You can see that work in progress.
As you near Red River, you will pass several areas where rainy season flash floods regularly carry loose, yellowish gravel into gulches and the Red River. Just past Elephant Rock Campground, look for Elephant Rock, a large quartz-latite block, on the ridge to the north.
From all over the Town of Red River you can see Hottentot Wash, a huge yellow scar — another remnant of the Questa Caldera — on the mountain to the northwest. Hottentot Wash is what’s left behind of massive landslide that dammed up the Red River — the town is built on a a silted up lake bed.
If you have time for another side-trip, head up Highway 578 to the Upper Red River Valley. A little over a mile up that road you can find the turnoff for the Old Red River Pass. Built in 1916 by the U.S. Forest Service, this narrow, unpaved road with its switchbacks and its occasionally steep grade was considered an engineering triumph in its day. (Normally a 4×4 road, it is closed for repairs.)
Head up Highway 38 on Bobcat Pass for 18 miles to Eagle Nest. According to “The Enchanted Circle — Loop drives From Taos” (see info below), “Precambrian rocks over 1 1/2 billion years old are exposed throughout these mountains.”
As you head up the pass, you can see Gold Hill, elevation 12,711 feet, in your rearview mirror. According to John Miller, although Gold Hill still stands out as a prominent feature on any satellite photograph of northern New Mexico, it actually dropped over 3,000 feet following the cataclysmic explosion of the Questa Caldera.
“Twenty million years ago, Gold Hill was really big,” Miller says.
On the other side of the pass just after the big curve, look for an outcrop of pink rock on the left. This is a popular spot for collectors because of its collection of quartz and muscovite mica (pink flakes).
As you reach the bottom of the pass, you start to see Baldy Mountain, elevation 12,441, once the site of several gold booms in the late 1800s. Past the Moreno Ranch East and Flying Horse Ranches, look for a sign noting the E-Town Museum. This, the rocky remnants of the Mutz Hotel and a few buildings are all that remain of Elizabethtown, a gold mining boom town that was once the Colfax County seat.
To supply large amounts of water for the hydraulic mining that was used at E-Town, an aqueduct — the “Big Ditch” — was built in 1868 – 69 from the Upper Red River Valley across the mountains to the Moreno Valley.
Parts of it can still be seen on the drive down Bobcat Pass and in the Upper Red River Valley.
Eagle Nest Lake came into being when Charles and Frank Springer built a dam in 1918 but the Moreno Valley itself was once the site of a great lake that formed when tectonic pressures lifted up the mountains on either side, then lava flow dammed up the valley.
At the intersection of Highways 38 and 64, take a left for another side trip 12 miles down Cimarron Canyon to the spectacular Palisades Sill in Cimarron Canyon State Park. Its columnar joints were caused by the slow crystallization and cooling of molten rock in the earth’s crust followed by millions of years of erosion, freezing and thawing which caused the fine horizontal joints.
Head back to Eagle Nest then 10 miles south past the turnoff for Angel Fire. From there you can take a side trip to Coyote Creek State Park along NM 434, 17 miles south of Angel Fire. According to the New Mexico Bureau of Geology & Mineral Resources webpage on the park’s geology, Coyote Creek State Park is at the bottom of Guadalupita Canyon where Coyote Creek runs through mountain meadows and forests before joining the Rio Mora on its way to the Canadian River. Basalt cliffs crop out along the mesa edge that is visible from the park and broken-off basalt boulders can be seen throughout the park. The basalt is black, fine grained, vesicular, and consists of olivine, clinopyroxene, augite, plagioclase, magnetite, and rare biotite and quartz. Look closely at the basalt, and you will see visible laths and euhedral-shaped crystals.
Head back to Angel Fire and turn southwest onto US64. For the next 3 miles on the climb up Palo Felchado Pass, you can find marine fossils in the rocks along the road, especially in the shale.
From the top of Palo Felchado Pass, the highway takes you 15 miles to Taos and the future seaside vistas of the Rio Grande Rift.
Note: Most of the geologic information for this article came from “Roadside Geology of New Mexico” by Halka Chronic (1987 Mountain Press Publishing Company) and “The Enchanted Circle — Loop Drives From Taos: Scenic Trips to the Geologic Past No. 2” by Paul W. Bauer, Jane C. Love, John H. Schilling and Joseph E. Taggart, Jr. (1991, New Mexico Bureau of Mines & Mineral Resources) The second book is out of print but is available on CD-ROM. Call 505-835-5490 or check geoinfo.nmt.edu/publications