MESA VERDE NATIONAL PARK- We've hiked down a steep trail, climbed up a ladder with dizzying exposure and squeezed through an 18-inch crevasse to reach this place known as Balcony House.
Here, more than 900 years ago, a people who had been dwelling on the top of the mesa for centuries began to build homes and towns in massive cliffiside alcoves. Why? Nobody knows.
And why did they abandon them after less than a century? Nobody knows that either.
That's part of the allure of visiting Mesa Verde National Park in southwest Colorado. Like everyone else, we came to ogle some of the best-preserved and most visually stunning archaeological ruins in North America. You can see some without straying far from your car.
But walk through one or two on a guided tour, and you realize the cliff dwellings have a deeper story to tell. It's a story of growth and abundance, of dwindling resources and a changing climate.
It's also a story that ends in a question mark. Finding your own answers is the fun part.
Saving 'works of man'
Mesa Verde means "green table" in Spanish, though it's unclear if the Spanish found the ruins.
After miners and cowboys discovered the ruins in the 1870s, archaeologists and relic seekers, and later, tourists, descended on the area. Colorado Springs journalist Virginia McClurg formed the Colorado Cliff Dwellings Association in 1900 to preserve the ruins.
The concept of preservation was different then, because McClurg had a 40-room cliff house near Mesa Verde taken down and relocated to Manitou Springs, where it remains today.
In 1906, President Theodore Roosevelt created Mesa Verde National Park. It was the nation's 11th national park, and the first established not for nature, but to "preserve the works of man."
Today, the park protects 5,000 archaeological sites, including 600 cliff dwellings - from tiny one-family homes to the sprawling Cliff Palace, a 150-room wonder that has to be seen to be believed.
Take your time
It's important to have two things when visiting Mesa Verde: at least one full day and a plan.
After passing through the dusty hamlet of Mancos along U.S. Highway 160 and turning off the road, we stopped at the recently completed visitor center before the park gate.
To protect the frail structures, the National Park Service requires visitors to take guided tours at three of the most popular cliff dwellings. Pay the $3 per-person tour fee and sign up to see the Cliff Palace, which is the largest ruin, the aforementioned Balcony House, which requires all manner of climbing and crawling to see, or the Long House, the second-largest.
It was late in the afternoon, and it's more than an hour's drive on slow, twisty roads to reach any ruins, so we decided to see only the Balcony House on our first day.
We passed Morefield Campground, the only place camping is allowed in the park, stopped to enjoy the view of the La Plata Mountains from an overlook, and checked in at Far View Lodge.
This hotel is the only lodging on the mesa. Each room has a balcony with, you guessed it, a far view into four states, and there is a restaurant and bar. The rooms are a bit rustic and fortunately come with no televisions; there is no better base of operations for a couple of days exploring Mesa Verde.
After our tour, we watched the sun set over Sleeping Ute Mountain in the distance and called it a night.
Plenty to see
When they first came to Mesa Verde 1,400 years ago, the people known as Anasazi, or Ancestral Puebloans, lived in pit houses. Farming on the mesa proved prosperous, and they progressed to elaborate stone buildings as the population exploded to several thousand people by 1100 AD.
Our second day, we took the Classic Pueblo bus tour offered by park concessionaire ARAMARK, which started on the Mesa Top Loop, where you can see excavated remains of these earlier homes. While not as striking as the cliff dwellings, this is just as big a part of the story. There was a huge, vibrant community living on top of the mesa for centuries, until something compelled people to seek the shelter of the cliffs.
But what? The question reverberated through the tour group as we gathered for a hike through the Cliff Palace.
The first time we rounded a bend and saw this cliff city, I was in awe. Hidden in a giant alcove was the grandest ruin you're likely to find in an America whose history begins in 1492. Walking among the still-standing walls and towers, tiny bedrooms and 23 kivas, circular ceremonial rooms, it's hard not to admire the builders.
These were people with no written language and an average life span of 32 years, with rotten teeth and a 50 percent infant mortality rate, working with wood, clay and mud. Yet their structures have survived 900 years of harsh desert weather.
Reluctantly, we climbed the ladder out of the alcove and got back on the bus. We saw a few more sites, but the Cliff Palace remained in my mind for a long time.
Living on the margin
On the third day, we drove to Wetherill Mesa, the most remote area with road access, for our final tour, of Long House. We rode the tram, met our guide and began the climb down into the valley.
The tour guide gave the now-familiar talk about the history of the cliff dwellers, but my mind was elsewhere.
While it's a mystery why the Anasazi began moving to the cliffs, the even greater mystery is why they left.
Despite the obvious effort to build the cliff dwellings, archaeologists believe they were occupied for less than 100 years. By 1300 AD, Mesa Verde was abandoned.
Were the cliff dwellings a defensive measure as Mesa Verde degenerated into conflict? Did a drought in the final quarter of the 1200s compel them to leave?
As we made the long drive back to modern America, I thought about the most plausible notion, one extolled by rangers on all three tours we took. It's the same thing that has doomed so many civilizations: resources.
After hundreds of years, maybe the wildlife and trees were gone, the soil was depleted by agriculture and water was increasingly scarce. It's hard to imagine simply abandoning the fruits of so much work, but this was life on the margin, with no safety net. Families either survived or starved.
The cliff dwellers went south into New Mexico and Arizona. Modern Hopi, Zuni and other Pueblo Indians trace their ancestry to the Anasazi.
The cliff houses were never occupied again, a silent testament to the richness of these ancient people who lived off the land, and what may have happened when the land had nothing more to give.