Rock art paintings discovered at La Alberca connect the team’s study sites to an even older history dating back to the late Holocene period. With total station and GPS equipment, the team is precisely mapping the position of each painting to ultimately create a 3D walk-through of the site. Photo courtesy of MEXECRI.

If Dr. Tricia Gabany-Guerrero and Dr. Steven Hackenberger have their way, within the next five years, everyone will know the name “Purépecha” and what it symbolizes in Mexican history.

In the history of Mexico, it is the Maya and Aztec civilizations that rule--they have dominated scholarly work, archeological projects and brought tourists in droves to marvel at their ruins. Yet the Purépecha* Empire was a prominent rival to the Aztecs, the only regime to deaden the Aztecs’ desired expansion into the central-west region of Mexico. That fact is just one of many that is typically missing from historical accounts of Mesoamerican civilizations specific to that region of Mexico. Dr. Guerrero, for one, wants to give the Purépecha their rightful due in history.

“The Purépecha Empire has long been an anomaly in Mesoamerica,” she says. “But [it was] a significant force. [It] bordered the Aztec Empire and successfully fought off the Aztecs for 50 years before the Spanish invasion. Far from slight, this empire developed several impressive ceremonial complexes and political capitals, exerted control over major trade routes that extended throughout Mexico, and grew a territory covering more than 75,000 kilometers square.”

The Topcon Hiper Lite Plus integrated GPS and RTK receiver can operate effectively even in heavy forest canopy. Photo courtesy of Topcon.

Unveiling History

An anthropologist at the University of Connecticut, Guerrero and a small international team of archeologists, paleosteologists, geomorphologists, chemists and graduate students have been digging up dirt on the Purépecha people--both literally and figuratively--since 2001. In close collaboration with the Mexican Native American Community of Nuevo San Juan Parangaricutiro (CINSJP), the team is conducting field investigations and artifact sampling and analyses to focus not only on demystifying the origins of the Purépecha Empire but reconstructing its world through 3D technology, allowing people to live the Purépecha life for themselves.

To reach that goal, however, they must first unearth that life. And although Guerrero’s group has already uncovered notable finds, she says it wasn’t until the addition of advanced total station and GPS survey technology from Topcon (Livermore, Calif.) in 2005 that the group could prove that the Purépecha are a more complex civilization than ever understood previously.

“We shouldn’t be finding the types of artifacts that we are finding at this particular site,” Guerrero explains. “It completely defies our current understanding of the Empire itself.

“The Topcon equipment has greatly assisted us with these finds because we now understand more clearly the spatial relationships between structures in a region as well as structures in a controlled site,” she continues. “And we can relate that to a broader context of cultural issues in the region such as trade or mining. I think our discoveries will change our ideas about this particular civilization and how it related to the Aztecs as well as to its own administrative system. It’s thrilling.”

The study site of La Alberca, which includes the La Loma and Ambrosio excavation fields, is where Guerrero and her team discovered cliff paintings and a ceremonial residence.

A Primer of the Purépecha Territory

Situated among the fertile volcanoes of Michoacán, stretching between the large Lerma and Balsas Rivers and around Lake Pátzcuaro, one of the largest inland lakes in Mexico, the Purépecha state was the second largest state in Mexico at the time of the Spanish conquest. Founded in the early 11th century, the Purépecha flourished from 1100 AD to 1530 AD, when the Empire lost its independence to the Spanish in 1530. In 1543, it officially became the governorship of Michoacán (from the Nahuatl name for the Purépecha state, Michoacán means “place of the fish,” a name bestowed on them by the Aztecs).

Due to its geographic location and various cultural influences within Mesoamerica, the Purépecha state had many distinct cultural characteristics that distinguished it from other Mesoamerican cultural groups, including language, pottery and a tendency to build round pyramids rather than trapezoid-shaped pyramids. Excellent craftspeople in many materials, they are particularly noted for being among the best technically skilled Mesoamerican civilizations to use metal for tools and ornamentation.

Though its isolation afforded Purépecha its cultural distinctness, it has also allowed it to go relatively unnoticed by the world’s scholars. Although a number of archeological digs have been done in Tzintzuntzan, the former Purépecha capital along Lake Pátzcuaro, as well as in Zacapu and La Piedad, Guerrero says that until her team began its investigations, no significant exploratory work had been conducted in their area of interest since the 1800s.

That lack of exploratory work has left Guerrero’s team with very little historical and spatial information to guide them, save a few general topographic maps from Mexico’s official mapping, geography and population agency, old aerial photos and local drawings of the cultural geography of the region.

Topcon’s GPS technology enabled the team to better map its findings of the Purépecha world. Photo courtesy of Topcon.

A Good Cause

Given the sites’ remoteness and weather constraints, and the team’s short fieldwork seasons and tight budgets, the group has consistently tried to adopt technologies that will help them work more efficiently, particularly total station and GPS equipment that provides a greatly needed mapping element in the field. In 2004, the team secured a handheld GPS unit from another university department. But, Guerrero says, it wasn’t powerful enough to provide them with adequate accuracy.

“We are very remote and often down in holes so satellite reception can be an issue,” she says. “We needed very powerful and sophisticated positioning equipment to help us create 3D positions of artifacts, which can assist us with dating and determining their use as well as the relationships between artifacts--particularly for the cliff paintings we are finding. The equipment is critical to the work and saves time and money in the long term.”

With the 2005 spring field season fast approaching, Guerrero began a search to find vendor support for her research and found an equally intrigued party: Peter Wallace, sales director of survey for Topcon. Already a supporter of other archeological research on the Maya for several years, Wallace says Topcon was eager to support such a unique and important project.

Familiar with the environmental constraints and special equipment needs on archeology projects, Wallace chose to provide Guerrero and her team with the technology that would best benefit them in the field: Topcon’s GPT-3007W reflectorless total station and the Topcon HiPer Lite Plus integrated GPS and RTK (real-time kinematic) receiver.

“When you only have a few weeks to explore a vast, remote area and limited resources with which to do it, you need equipment to enable you to be very productive and efficient without sacrificing precision,” Wallace says. “The GPT-3007W and HiPer Lite Plus are both very well-suited to such challenges.

“They both use Bluetooth wireless communications so they are cable free,” he explains. “In addition to being very small and very light, the GPS receiver accesses both GPS and GLONASS [the Russian satellite navigation system] constellations, providing the team with more available satellites to quickly obtain fixed positions--even under heavy canopy and difficult terrain where you can’t typically achieve that. The total station also has a very powerful non-prism measuring capability, which allows measuring and capturing of data without having to use a prism. It is also waterproof and dustproof, which is critical for that environment.”

Topcon also committed its own people to the project. Two people were sent to the location to help set up the equipment and run it, and provided a day’s training.

Domestic ceramic artifact samples found at the La Loma site. GPS and total station technology from Topcon aided in the search and recordation of such finds.

A Total Difference

To date, the team has investigated three different sites, but for the May-June 2005 field season, they chose to test Topcon’s GPT 3007W at the La Loma and Ambrosio sites, a three-hectare area about 100 km west of Lake Pátzcuaro that the team has concentrated on for the past three years.

Each morning they set the unit on a known control point and mapped control within the site. Mapping activities were dictated by what new finds the day would bring; sometimes they consistently mapped structures and artifacts throughout the day, and other times it was done all at once at the end of the day. Because the total station is cable free, Guerrero says it afforded the group the flexibility they needed to easily and quickly move the unit around the sites.

It was also essential that the positioning equipment be easy to operate, reliable, consistent in operation and, of course, accurate.

“[Since] we work so remotely, if we encounter equipment problems, we can’t rely on cell coverage or Internet access to resolve them,” Guerrero says. “The Topcon total station was very easy to use and it consistently provided outstanding results.”

By the end of the initial test excavations in 2005, the team established the existence of extensive Late Classic and Late Postclassic communities (700 AD and 1450 AD). In particular, they found evidence of both ceremonial and residential sites, organized households and entire communities as well as patterns of regional interaction and trade.

While mapping this evidence with the Topcon GPT-3007W was “easy,” according to the group, the total station alone did not allow them to relate that map to real space or time. They needed both total station and GPS equipment to precisely locate and map the artifacts within controlled excavation zones.

Integrated Intelligence

For the May-June 2006 field season, Guerrero and her group connected the missing link with Topcon’s HiPer Lite Plus GPS receiver. Already versed in GPS technology, the team of 12 was able to quickly put the GPS unit to work in the field, affording them maximum investigation time. Again, the focus was on the La Loma and Ambrosio sites.

Each morning, dedicated team members set the ground control with the total station and began taking shots. Using plains archeology methods, they first ran a plow over a select area of interest and then one person walked the field with the GPS receiver looking for any artifacts on the surface. When an artifact such as a ceramic piece or obsidian flake was found, they used the GPS receiver to record and map its exact location as well as the tentative boundaries of the controlled site. The total station was then used to better map key areas.

The ability to freely roam with the GPS unit and instantly record artifact locations was particularly advantageous for some areas where it was difficult to even keep up with the finds.

“In just one ten-meter-square section of the field, we came up with around 100 to 150 pieces of ceramic, and in another part of the field we discovered 200 to 250 pieces of obsidian,” Guerrero recounts. “With the GPS we could just point and shoot and instantly create an accurate map of their positions to within fifty centimeters. That immediately gave us a sense of the density of particular kinds of artifacts.”

Based on the specific artifact densities, the team could then pinpoint where to begin more detailed excavations by digging pits. For the pit work, Guerrero’s group used the total station and GPS technology together to create very detailed maps of both the hole and all artifacts found within it. Using the total station, they mapped the four coordinates of the top of each layer and the bottom of each layer. Each artifact found was then shot with the GPS to map its specific location within the particular pit. Having that mapping detail enables the team to associate not only the positions of artifacts with the stratigraphy of the pit but across the entire site.

“With the combined total station and GPS results, we have been able to create a spatially-constructed statistical analysis of artifacts within and outside the structure,” Guerrero explains. “Now we can ‘see’ the relationship between social space and objects, such as obsidian blades and clay pipes, both of which were used for intense ceremonial rituals from about 1400 to about 1521 AD. And by being able to process the data in the field so quickly, we’re able to change our research strategy to better plan future work.”

One of last year’s most exciting discoveries is a prime example of that. Using the same integrated total station/GPS methodology, the team pinpointed a particular area at the La Loma site that warranted further investigation. What they uncovered was “a complex elite residence”--a structure unlike a normal household bearing very thick walls, a series of complex rooms with unusual passageways, a dense concentration of clay pipes and unique pottery. The evidence leads the team to believe that they unearthed an elite ceremonial residence.

This month, when the team begins its next field season, the top priority is investigating this structure further to hopefully confirm what they already believe. Guerrero is hopeful that the Topcon equipment will again be a critical part of the field unit.

“The total station and GPS technology has completely revolutionized our ability to work,” she says. “It has significantly improved our mapping ability. Most importantly, we can now put our data in a spatial context. We can relate specific data about structures, features or artifacts to a broader context of the geography of the region and the social climate of the time.”

It seems clear that Guerrero and her team are well on their way to unearthing the mysterious origins of the Purépecha people. Indeed, it may not be long before the Purépecha Empire rightfully and equally finds its place in Mexico’s ancient history, along with the Maya and the Aztec.

* The Purépecha Empire was formally known as the Tarascan Empire.

To date, all project work has been funded by the National Geographic Society for Research and Exploration, the Foundation for the Advancement of Mesoamerican Studies, the University of Connecticut, the University of Central Washington, and CINSJP. Donations to continue the work are welcome through the Mexican Environmental & Cultural Research Institute (

Purépecha Project Team Members:

Dr. Steven Hackenberger, Archeologist, Central Washington University. Chief Excavation Expert.

Dr. James Chatters, Paleosteologist, TECI, Seattle, WA. Chief Osteology Expert.

Dr. Lisa Ely, Geomorphologist, Chair of Geology Department, Central Washington University.

Dr. Anthony Newton, Geochemist, University of Edinburgh Scotland. Research Fellow.

Narcizo Guerrero-Murillo, doctoral

candidate, University of Texas at El Paso,

Environmental Science & Engineering. Member

of the Comunidad Indigena de Nuevo Parangaricutiro.

Dr. Francisco Martinez Gonzalez, Department Chair, Hydrology and Mapping, University of Guanajuato, Guanajuato, Mexico.Dr. Pedro Cid Aguero. Chemist, University of Connecticut.