Approaching the Mayan ruins by dugout canoe, O'Kon, CE '61, immediately realized the significance of the rock formation.
"That's a bridge pier!" he declared.
That was in February 1989, O'Kon's first visit to the Mayan ceremonial center Yaxchilan (pronounced YashSHE- Ian), which flourished during the classic Mayan period between 500 and 700 A.D. Archeologists had been studying the site for more than 110 years, and the mound of rocks had been dismissed as a minor mystery, possibly explained as a once-dry part of the city engulfed by a shifting river.
A former chairman of the forensic council of the American Society of Civil Engineers, O'Kon turned to modern technology to help prove a bridge existed, a technique he has used Professionally. O'Kon is president of O'Kon and Co., an Atlanta engineering firm that has conducted such forensic engineering investigations as the deadly walkway collapse at the Hyatt Regency in Kansas City, Mo., in the 1980s.
He compiled field information collected at the Mayan site and used computers to integrate archeological studies, aerial photos and maps to develop a three-dimensional model of the site and determine the centerline, discover the location of the bridge abutment and hypothetical construction of the bridge.
O'Kon made a startling discovery: The Mayans built the longest bridge span in the ancient world.
The pre-Columbian bridge was a 600-foot, hemp-rope suspension structure with two piers and three spans built in the seventh century, O'Kon said. Connecting the Yaxchilan ceremonial center in Mexico with its agricultural domain in what is now Guatemala, the bridge had a middle span of 203-feet-the longest span in the world for almost 700 years. In 1377, a bridge with a longer span was built in Europe, O'Kon said.
The Mayan city was strategically located on high ground. An omega-shaped bend in the river circles the city on three sides, and its only land approach is cut off by steep mountains. Heavy rains made the Usumacinta River virtually impassable from June until January.
"Six months of the year, there is almost 170 to 200 inches of rainfall, and the river is 40 feet above its banks," O'Kon said. During flood stage, Yaxchilan became "an island city," he said.
A bridge was essential for the inhabitants of the densely populated city to have year-round access to their domain, their agricultural fields and for commerce, O'Kon said.
The rock pile--12 feet high and 35 feet in diameterwas part of a masonry structure, O'Kon said. Aerial pho tos taken in 1992 revealed the remains of a second support pier on the opposite side of the river, which was almost completely submerged.
Both piers were constructed with an interior of castin- place concrete and an exterior of stone masonry, O'Kon said. "They formed a circle and filled the inside with cast-in-place concrete forming pillars, just like they did their temples and pyramids."
Identification of the bridge abutment that led to the city's grand entrance was the "clincher" necessary to reconstruct the complete ceremonial function of the bridge, O'Kon said. A platform situated in an ancient plaza area and located on the centerline of the bridge was a "classic bridge-approach structure," he said. A stairway leading to the top of the platform and covered in hieroglyphics was also discovered. These stairs were the ceremonial gateway to the city. Carved stone devices were also found, which O'Kon believes were guide- ways for the rope-cable suspension bridge.
"I plugged all of that into the computer," O'Kon said. "I digitized the maps and put in all the information. Everything lined up-the pillars, the abutments and the ceremonial platform."
Artist David Morgan, who had been to the Yaxchilan site, drew an illustration of the bridge based on the computer renderings.
O'Kon, who has been exploring and studying Mayan archaeology and engineering for almost 30 years, worked at the Yaxchilan site with Dr. Nicholas Hellmuth, director of the Foundation for Latin American
Anthropological Research at Brevard College in Cocoa, Fla. In January 1994, he presented a paper on his study of the Mayan bridge at an international Maya Symposium at Brevard College.
O'Kon published his findings in the January 1995 issue of Civil Engineering, and National Geographic magazine wrote an article in its October 1995 issue highlighting O'Kon's solution to the "riddle of the rocks."
Articles about the discovery appeared in more than 140 newspapers, and O'Kon participated in a four-hour conference on the Internet in which he fielded questions from around the world.
The design requirements for the Mayan bridge parallel 20th century bridge-design criteria, said O'Kon, who bristles that archeologists have traditionally classified the Maya as a "stone age" culture because there is no evidence they manufactured metal tools. He stated that the nearest iron ore deposits are 1,500 miles away. Instead of iron, O'Kon said, Mayans created tools out of a substance harder than steel – jade.
O'Kon refers to the Maya culture as "technolythic" rather than follow conventional archaeological classifications.
"The Mayans were very sophisticated mathematically and scientifically," O'Kon
said. "They had the concept of the number zero 700 years before the Europeans--without the influence of the Arabs or Chinese.
Mathematically and astronomically the Maya were very advanced. In my opinion, technologically there had to be a parallel.
"The Yaxchilan society was highly developed," he added. "It was a fabulous city with gleaming white temples on terraced hills. The buildings were covered with white stucco with colors and sculpture."
O'Kon's interest in archaeology began in high school and continued during his student days at Georgia Tech, where he was a cartoonist for the Technique and art director of The Rambler humor magazine. It wasn't until after he had graduated from Tech that he began to visit archeological sites, traveling to both Europe and North Africa.
"I went to Mexico in 1967; that's when I actually started having a chance to be exposed to the ruins," he said. "I didn't explore for anything new and undiscovered. I just wanted to see the sites that were in all the guidebooks. Over the years, I built up my knowledge of the Maya."
His wife, Carol, is an anthropologist who now works with the firm and accompanies O'Kon on his explorations. "She helps me to remain in anthropological perspective and keeps me honest," he said.
O'Kon's company did the engineering design for two high-profile projects at Georgia Tech: the Wardlaw Center and the Kessler Campanile. The firm is pioneering designs in shaped aviation-maintenance hangars.
Throughout his explorations, O'Kon has kept journals of his archeological adventures, illustrated with detailed sketches--and humor.
One journal entry records an encounter with "The Guardians of Widows and Orphans"-- two Guatemalan guerrillas, armed to the teeth" and wearing Chinese communist fatigue caps. A sketch in the journal labels the taller one "the shooter" and his companion "the brains."
"I approached cautiously; the others came up slowly and silently," the journal reads. "I passed the word back for Tammy to come to the front. We listened and watched as Jaime talked with the guerrillas. My Spanish was sufficient enough to catch some of their words. The leader of the guerrillas said, 'We are guardians of the widows and orphans,' and 'We are concerned that you (us) may be agents of the CIA and may tell the army of our location. If you tell the army, they will bomb the ruins and destroy the antiquities.'
"The two guerrillas were a team," the entry said. "The older, shorter man (45 years old) spoke clearly and convincingly. This speech was a matter of doctrine and had been repeated many times. He stood with his M-16 resting across the crook of his arm in a horizontal position, just slightly away from a line directly into our stomachs. As he talked, his big hands gestured constantly, always held closely together and always within centimeters of the trigger of his M-16. I watched his hands for tenseness and for movement toward his trigger. This man was the 'brains' of the operation. The other was slightly younger (about 40 years old). His intelligence quotient was slightly above that of a howler monkey."
Finally, the guerrillas decided to allow the group to continue.
"As we passed by, the guerrillas stepped aside," O'Kon wrote. "Buckaroo gave them a soul shake. Vernon turned to me and asked me to ask the guerrillas if it was okay to take a photo. I told him, 'Don't even ask."'
Another exploration occurred during the Zapatista uprising in the Mexican state of Chiapas.
"We had to go through two roadblocks of the Mexican army, which scared the hell out of me, because teenagers with machine guns always scare me," O'Kon said. "We had a letter of safe conduct that worked with the Mexicans. The Zapatistas didn't care. They were just nice guys who were having a revolution."
O'Kon is now working to uncover a lost road system he says once connected the vast Mayan empire. He is using satellite images and remote sensing techniques to reconstruct the pre-Columbian transportation system.
O'Kon has started his project by developing a remote sensing signature of the 100 kilometer sacbe, or road, that runs between the ancient Mayan cities Coba and Yuxuna. The extensive road system stretches over hundreds of miles, measuring 30 feet across in some places and rising as much as eight feet above ground level, O'Kon said.
"The Maya sacbe or roadway system has been the subject of controversy and admiration for their advanced engineering techniques," he said. "Historical chronicles prepared by the conquistadors suggest a network of all-weather roads that interconnected Mayan urban sites."
O'Kon said many archeologists believe the sprawling network of roads was built for ceremonial purposes. But some major Mayan cities had populations of 100,000, and an effective highway system was necessary for commerce, communication and rapid military deployment, he said.
"These roads had fortifications and interchanges, culverts and all kinds of good stuff," O'Kon said.
O'Kon said his training as an engineer gives him an invaluable point-of-view. I look into the architecture and engineering and technology of the Mayans with a different perspective than the art-trained archeologists."
Reconstructing the network of lost roads could also result in the discovery of lost Mayan cities, O'Kon said. Time and technology, he said, will yield the answers.
Learn more and see more bridge images in O'Kon's website