If you've read my biography, you know my work frequently takes me to national parks. From time to time, I'll post articles that have evolved from those visits. The first comes from my visit to Mesa Verde, a park of ancient dwellings that spark the imagination.

    MESA VERDE NATIONAL PARK, Colorado — Though the sun-baked oak rungs seared my palms, letting go was not an option as I climbed toward the Balcony House. The wooden ladder was only 30 feet long, but it stretched back roughly 800 years to the time of Kublai Khan and Marco Polo and the people that once lived along this remote mesa top.

    Minutes after stepping off the ladder, I stood on the cliff dwelling’s plaza with its airy terrace overlooking Soda Canyon near the southern tip of Mesa Verde National Park. A thigh-high balustrade of rock separated the terrace from the canyon’s void, while far off to the east, the San Juan Range’s snow-capped peaks tantalized on this hot summer day.    
    A southerly tilted layer cake of salmon-hued sandstone and umber-tinted shale laid down 65 to 70 million years ago by a shallow sea, Mesa Verde actually is an assemblage of 15 fingers that erosion cut deeply into the bedrock. Fifteen hundred years ago Native Americans settled on the wildlife-rich mesa top. They lived within semi-buried pit houses around A.D. 500, then moved into adobe villages 500 years later. By A.D. 1,100 most of the mesa’s estimated 3,000 to 5,000 inhabitants had gone under the rim.
    Perhaps it was fear of attack — or merely shelter from the rain, snow and glaring sun — that drove them into the alcoves perched precariously on the canyon lips. Whatever the cause, within the rock chasms that pepper the Cliff House sandstone formation they erected hundreds of stone honeycombs, with interconnecting apartments, granaries and subterranean chambers called “kivas” that played a spiritual role in their lives.
    Built early in the 13th century, the Balcony House today harbors only the wind, mice, birds and lizards. But eight centuries ago, it was one of many villages that clung to Mesa Verde’s sandstone alcoves.    
    Mesa Verde, which means “green table” in Spanish, is an outdoor museum of hallowed ground. Twenty-four tribes claim spiritual ties to the mesa that soars some 700 feet above southwestern Colorado’s surrounding lowlands.
    Here the National Park Service preserves a cultural landscape we don’t fully comprehend. Where a society once flourished there now is only evidence of a vanished people: ruins dotted with kivas, towers, and countless relics from a people known simply as “Ancestral Puebloans.”    
    Then and now Mesa Verde is a demanding landscape. It is torturously dry at times, grooved by rugged, talus-littered canyons, and susceptible to wildfire. Yet the Ancestral Puebloans, who lacked the finely woven cottons and silks of their far-flung global contemporaries, were fearless architects, masterful potters and basket makers and tenacious survivors.    
    They tended patchwork fields of corn, beans and squash, and hunted deer and rabbit. Plants provided not only food and medicines but fibers to weave sandals and baskets, make rope and fashion paint brushes for decorating their pottery in bold and distinctive black and white patterns. They built water catchments and relied on the stars to tell them when to plant their crops.    
    But these Native Americans are best remembered today for their architecture. Scattered across Mesa Verde are nearly 5,000 archaeological sites, including a sprawling village complex at Far View and the maze-like, but mysteriously unfinished, Sun Temple. Six hundred or so cliff dwellings have been identified.    
    Without levels, tape measures or bags of Portland cement, the Stone Age masons used river-rock hatchets to cleave bread-loaf-sized sandstone blocks, stacking them to raise elaborate shelters. Logs of juniper became roof beams and, subsequently, flooring for the next story of apartments. 
    As clans grew, the men would slowly expand an outcrop of a few connected rooms into sprawling villages. Once the rooms were built, women would plaster and decorate the interior walls.    
    In his search for coal, geologist S.E. Osborn reached Mesa Verde in 1884 and was astounded by the sight of “thousands of cliff houses. Every available spot is covered with them.”    
    Reaching the dwellings, he soon discovered, was not easy.    
    “In climbing the cliffs on the route I took, I found footsteps cut in the rock and think the people who lived here must have gone up in the same way that I did,” Osborn recounted. “When I arrived I found a perpendicular cliff about 40 feet high, which I climbed by the aid of a rope, which I threw onto a small cedar at the risk of breaking my neck. But I was well repaid for my trouble by finding a building at least 250 feet in length, six stories in height in the front and from four to six rooms deep into the cliff.”    
    Osborn might have been describing Cliff Palace. The 151-room palace, the park’s largest cliff dwelling, is the most notable fortress of the Ancestral Puebloans’ Mesa Verde empire. Smaller dwellings are wedged into numerous alcoves found in Soda, Cliff, Navajo, Wickiup, Long and Rock canyons.    
    Only five of the cliff dwellings — Balcony House, Cliff Palace, Long House, Spruce Tree House and Step House — are open to the public. Scores of others can be seen from park roads, seemingly hanging on cliff sides, but perilous approach routes and unstable ruins keep them out of public reach. An exception likely will be made during the park’s centennial celebrations in 2006 as park officials are thinking of allowing horseback rides or backcountry hikes to take visitors to the Spring House that looks down upon Long Canyon.    
    Time was deconstructing these dwellings when they were discovered by Osborn and area ranchers, Al and Richard Wetherill, in the 1880s. Though the five dwellings open to the public have been meticulously reconstructed, when Osborn and the Wetherills stumbled upon them, many of the ruins consisted of just a few standing dwellings surrounded by piles of dust and rubble.    
    Today, thick, black smoke stains on the alcoves’ coarse walls show clearly where fires blazed for cooking and warmth. Centuries-old juniper beams, some a bit frayed on their ends, remain in place in many of the rooms, while ladders placed by the National Park Service mimic those that must have been used to enter rooms above the first story.
    At Long House, the inhabitants somehow drilled holes into the sandstone floor near the steps and chiseled small troughs to direct the water into these holes. Their wooden ladles dipped water neatly from these holes.    
    At Spruce Tree House, I descended by ladder through a two-foot by two-foot opening into a kiva and paused to let my eyes adjust to the dim light. Near the center of the roughly 15-foot-wide room stands a small deflecting wall that shielded a fire pit from air currents flowing into the kiva via a ventilation shaft. Near the opposite wall is the “sipapu,” a small hole in the ground the Ancestral Puebloans believed led to the spiritual Third, or Lower, World.    
    For a few minutes I stood in the darkness, sensing the setting’s spirituality. To be able momentarily to share that space with the ancient ones proved as awe-inspiring to me as did the setting back in the Balcony House, where I shared their view out into the world.