For three years in the mid-1970s, my wife and I were Catholic volunteers in a program called VIDA, a peace corps-type program run by the diocese of Pueblo, Colorado.
In the summer of 1977, one of my wife’s many sisters came to visit us and we took her to Mesa Verde National Park in the far southwest corner of the state.
My sister-in-law had just returned from a tour of Western Europe’s most famous sites, but nothing she saw there, she said, could compare with the magnificent beauty of Mesa Verde.
Mesa Verde National Park contains some 600 cliff dwellings, now abandoned but once the home of ancient Puebloans who lived there from about 600 to 1300.
The dwellings cling to the sides of canyons while on the mesa above, at least until recently, large stands of pinyon and juniper offer refreshing clouds of bluish-grey color, which offset the otherwise stark and arid landscape.
We climbed up into some of the cliff dwellings and peered down into kivas where the Anasazi, as they are sometime referred to, held their religious ceremonies.
In the park’s museum, we saw the famous black-on-white pottery, which is the famous trademark of these remarkable people.
One night, we gathered around a large campfire while a park ranger told us the story of the Anasazi.
The big mystery still not fully solved is why these ancient people abandoned Mesa Verde.
Was it because of increasingly ferocious raids by nomadic and warlike Utes or Apaches, or was it because of a severe drought that made it impossible to grow the corn and beans they depended on?
Mesa Verde is a rugged, semi-arid land where water can be scarce, and wildfires can blaze out of control scorching miles of forests and grasslands.
For a pueblo people having only stone-age technology of digging sticks and bows and arrows, there could have been only a narrow margin of error in the struggle to survive.
Scientists theorize that this area of the American Southwest experienced severe drought in the 1200s. They base this on the narrow growth rings found in old trees from that era and from the seams found in the timber cut by pueblo people.
Whether drought was the main cause or not, sometime around 1300. the people began to drift away to more promising lands to the south and east, establishing pueblos on the upper Rio-Grande, such as Taos, New Mexico, where Anasazi’s ancestors still live today.
In Mesa Verde today, another major transition is underway. A UNESCO report indicates the park is one of the most at-risk world heritage sites in the world.
A National Park Study declares that “Ongoing and future climate change will likely affect all aspects of park management, including natural and cultural resource protection, as well as park operation and visitor experience.”
Fire and beetle infestations are killing off large stands of the parks’ old-growth pinons that used to cover the mesa, over one-third is now gone, leaving a denuded landscape very unlike the one I saw in the 1970s.
Rock art painted by the Anasazi is being destroyed by wildfires.
Park officials and naturalists note that two species of squirrels are now gone, the juniper titmouse, a small songbird, has disappeared, and the Mexican spotted owl no longer visits Mesa Verde.
These changes may be the canary in the coal mine, representing the first signs of how a hotter and drier world may affect not just songbirds but us all.
Wildfires have always been a part of the natural cycle in this part of the American Southwest, so the increasing occurrence of destructive fires must be carefully measured with what is known of past fire activity.
Nevertheless, it appears that the current drought and fire cycle is exceeding past cycles in its intensity and possibly in its duration.
Already, the rapidly depleting waters of the once mighty Colorado River has led to urgent discussions among the states of the region — Colorado, Arizona, Utah, Nevada and California — on how to allocate the precious water for each area.
The challenges of a warming world may be more apparent in the American West, a semi-arid region historically vulnerable to severe droughts, but the Midwest is likely to see increasing problems, too.
Severe heat waves coupled with other factors may lead to alternating years of drought and heavy rainfall.
We — 21st century Americans — have more far resources and advanced technology than the Anasazi of the 13th century, but that doesn’t make us impervious to the natural world and its cycles, which may be beneficent in some historical periods but destructive in others.
Mr. Hoey is a member of Immaculate Conception Parish in Jefferson City.