The fascinating geology of City of Rocks State Park in New Mexico
Geological magic created the City of Rocks State Park in New Mexico
City of Rocks State Park, located in southern New Mexico, boasts a stunning, otherworldly landscape that has a fascinating geologic history. This is one of those places in New Mexico that just screams “Land of Enchantment.”
The rock formations in the Park were shaped by volcanic and sedimentary processes over millions of years. The relatively small park encompasses a one square mile area in the Chihuahuan desert region, at an elevation of 5,200 feet.
City of Rocks State Park is in the Mimbres Valley of the Chihuahuan Desert. Mimbres is Spanish for willow. Willow and other typical desert vegetation abounds in the park.
Explody Bits
OK, maybe I made up the word explody. Sometimes a new word just screams to be invented.
City of Rocks was formed about 34.9 million years ago by a very large, very intense series of volcanic eruptions. The ash falls created thick layers that became lithified (turned into rock), preserving the volcanic eruption record.
The silica-rich volcanic ash settled and compacted over time into a material known as tuff. This tuff, often light-colored and porous, is the primary rock that forms the unique "city" of rocks. The volcanic ash that was deposited eventually hardened into a material called volcanic tuff.
Current Rock Formations
One of the more interesting formations
Over millions of years, erosion sculpted the towering monolithic tuff formations into the current sculptured column. The columns resemble a natural cityscape, with narrow passageways and open plazas. Some of the rock pillars stand as high as 40 feet, creating a surreal environment that attracts visitors from all over.
This geology was a surprise to me, as I assumed by looking at the photos, that the rock was granite. While granite is also volcanic, it forms from magma that oozed and cooled slowly after burial, whereas tuff was formed from material ejected during more explosive volcanic eruptions.
The “City”
Imaginative visitors may see the rock formations as a small city, complete with houses, chimneys, courtyards, and streets.
Previous Inhabitants
Until 1200 A.D., Mimbres Indians roamed this area. For our historians, they left arrowheads and pottery shards as evidence of their culture. Spanish conquistadors also spent time in the area, carving crosses into the rocks. Please don’t do that.
Biology, Naturally
You know I can’t let go of my fascination of how biological diversity is affected by geology and geography. If you ever think the desert is nothing but sand, I urge you to think again.
Visit the State Park’s Botanical Gardens to see a sampling of southwestern plant and animal life. The park's desert botanical garden is home to cow's tongue and bunny ear cacti, Yucca, and towering Century plants.
Desert vegetation and wildlife, while perhaps not having the most variety, has some of the most well-adapted flora and fauna for their harsh environment. Yuccas, cacti, ocotillo, and juniper and evergreen oak trees are common throughout the park. After a wet winter or after a rainstorm, wildflowers abound. That is my favorite time of year in the desert.
A very large owl visited us while we were camping
The park is also home to many animals. Deer, antelope, javelinas, and jackrabbits are frequently seen in the area. Over 35 bird species have been identified, including bald eagles, golden eagles, hawks, horned owls, cactus wrens, roadrunners, and finches. Many of these birds live in cavities and crevasses in the rocks.
Be careful with your food while you are visiting, because ground squirrels, chipmunks, rabbits, or pack rats may invade and eat your supplies. Reptiles (rattlesnakes and lizards) and scorpions are also residents of City of Rocks. Leave them alone and they’ll return the favor. Keep an eye on pets and children, they haven’t developed a healthy fear of things that bite and sting!
I really missed out
Tony went camping at City of Rocks State Park with a group of our friends. I was with y family and had to miss the camping trip and I sure am sorry that I missed it! Fortunately, it’s just a few hours away from home. You know that I’ll be planning a trip there as soon as we stay home for more than a few hours at a time. Haha
Read more about Tony’s visit at his review of City of Rocks State Park.
