Project History

Scholars have been aware of the site we now know as Izapa since the 1930s. Culebro (1939:17, 31) presented drawings of two stelae from a site he called Guillén as well as a third that he attributes to the “toltec style” from Izapa (Culebro 1939:56). Izapa was so extensive that Culebro did not realize these monuments were all from one site.

A black and white illustration inspired by an archaeological find.
Izapa Stela 21, drawing by Ajax Moreno

Izapa was next explored by the Smithsonian Institute in 1941, when Stirling (1941, 1943) recorded 30 sculptures in a week of work. Six years later, Drucker (1948:154) excavated twelve trenches and identified Plumbate pottery at the site. Further, he recognized that, in contrast to the brown and black slipped sherds (that we now know date to the Formative period) he encountered in the southern part of Izapa, “The sherds lots from the northwestern group of mounds seemed different” (Drucker 1948:154).

The New World Archaeological Foundation (NWAF) undertook four seasons of excavation in the early 1960s and documented that Izapa was a large and complex Formative-period center (Ekholm 1969; Lowe et al. 1982; Lowe et al. 2013). Mexico’s Instituto Nacional de Antropología e Historia (INAH) returned to the site in the 1990s (Gómez 1995, 1996). The Late Formative Guillén phase (300-100 BC) is considered to be the apogee of the Izapa polity with a dozen plazas in use by this time (Lowe et al. 1982; 2013; Clark and Lee 2013).

The construction of platform mounds and temples created the Soconusco’s first urban center. Izapa’s plazas were lined with stelae and altars, many of which depict complex narrative scenes and legitimize rulership (Guernsey 2006). Then: “Some time before AD 100 there was a violent disruption of Izapa’s growth pattern, with central sections of the community abandoned…” (Lowe et al. 1982:308). Subsequent occupation shifted to Group F, north of the Formative-period site core, where a number of earlier stelae were reset.

Rosenswig initiated the Izapa Regional Settlement Project (IRSP) in 2011 to document changing regional patterns associated with the Formative-period Izapa polity. Three IRSP zones between the Cahuacán and Suchiate Rivers where surveyed (Figure 1).

Systematic surface collections were undertaken in each survey zone and the number of mounds with phase by phase occupation recorded in the piedmont (Rosenswig et al. 2013) and low hills (Rosenswig et al. 2015) zones. Hectares of occupation were recorded in the coastal plain zone (Rosenswig 2008). These data provide the basis for reconstructing relative population changes. In 2015, an additional lidar was collected and monumental centers were ground-truthed to date their occupation.

Read a Science magazine story on the project from 2014.

Formative Period Settlement

The IRSP has established regional patterns using lidar (light detection and ranging) and pedestrian survey data to reconstruct the political organization of Izapa and surrounding areas for the first time.

By the late Middle Formative Escalón and Frontera phases (750-300 cal BC), Izapa was the capital of a regionally organized polity consisting of dozens of monumental centers that employed the same architectural forms and site planning principles forming a four-tiered administrative hierarchy (Rosenswig 2016; Rosenswig and López-Torrijos 2017).

The initial architectural layout of Izapa and all lower-order centers in the polity followed the same plan (Blake et al. 2015; Rosenswig et al. 2015) and is somewhat related to what Clark and Hansen (2001) have called the Chiapas Middle Formative pattern (see also Lowe 1977).

Sites built according to the Izapa pattern had mounds forming multiple plazas arranged in a roughly north-south alignment with a large pyramid at each site’s north end sitting atop a platform and an E-Group at each site’s southern end. At Izapa, the southern E-Group was only recently recognized with the help of lidar technology (Rosenswig et al. 2013).

Formative Period Excavations

Excavations were undertaken by the IRSP in 2012 both north and south of Group B, the original center of Izapa (Rosenswig et al. 2018). This work dates the northern expansion of the site’s main platform (under Mound 30a) to the Terminal Formative Itstapa phase (AD cal 100-300) that resulted in a doubling of the platform’s size.

Further, we documented that there were three distinct construction episodes in the Terminal Formative expansion and that a central staircase and ramp were built of stone during the second episode. Buried below the Terminal Formative platform expansion was a white clay surface built during the Escalón phase (750-500 cal BC) and used through to Guillén times.

At the long, linear Mound 62, that defines the eastern edge of Izapa’s site core, we documented two episodes of Guillén-phase monumental construction. Buried below this construction fill at Mound 62, a hearth feature and stone alignment are dated to the late Middle Formative based on radiocarbon assays and the results of ceramic analysis.

Excavations at Mound 72 and 73 documented that Izapa’s E-Group (newly recognized with lidar data) was established in the late Middle Formative period and then significantly augmented during the Guillén phase.

The architectural program at Izapa saw its apogee during the Late Formative period, but was first established during the preceding centuries of the Middle Formative. Ten new AMS dates confirm the dating of the Escalón, Frontera and Guillén phases to between 750-100 cal BC.

Classic Period Settlement

The Classic period Soconusco is best known for the production of Plumbate pottery. This widely-traded ceramic ware is found in elite tombs through Mesoamerica (Dutton 1943; Neff and Bishop 1988; Shepard 1948:133) and is often associated with Fine Orange and lower Central American wares (Neff et al. 1999).

Shook (1965:190) long ago noted that “the heaviest concentration of sites with this type of pottery type occurs on the Pacific coastal plain and foothills between the drainages of the Rio Tilapia in Guatemala and the Rio Coatán in Chiapas.”

Neff (2002, 2003) has more recently documented that San Juan and Tohil Plumbate can be chemically sourced to specific river drainages within this zone. However, we still know virtually nothing about the political organization of the peoples that produced Plumbate ceramics, or their first millennium AD predecessors.

The IRSP survey results indicate significant population during the Terminal Formative Itstapa phase (AD 100-300) and initial Early Classic Jaritas phase (AD 300-400), followed by a virtual abandonment of both the piedmont and low hills survey zones during later Early and Middle Classic times (AD 400-700).

Then, a significant overall population increase is documented in all IRSP survey zones during the Late and Terminal Classic periods (AD 700-1000) when a large regional center is documented in the low hills zone with 46 secondary centers recorded within the 400 sq km of lidar data collected by the IRSP.

These secondary centers are formed by numerous small mounds creating both circular and square plazas, each with quantities of San Juan and Tohil Plumbate ceramics recovered from them. Late and Terminal Classic period centers, along with changing population levels provide the first glimpse of relative population levels and political organization in the area around Izapa.

There remains much work to be done if we are to understand the Soconusco region during the first millennium AD in a way that approaches what is known of the Maya area, the Valley of Oaxaca, or the Basin of Mexico. Results presented by  Rosenswig and Mendelsohn (2016) provide a preliminary view of regional organization and demographic patterns of the region.

Late and Terminal Classic-period occupation in the IRSP coastal plain survey zone was also substantial.

Initial survey results from a 28 sq km area documented that Late Classic remains cover the greatest number of hectares of any period (Rosenswig 2008). Subsequent expansion of the coastal plain survey zone, to now cover 70 sq km, has confirmed the initial findings. However, despite extensive occupation, no monumental centers are known from the coastal plain.

Recent work by Marx Navarro-Castillo (2014, 2015) documented a significant habitation at Miguel Alemán, a site with no monumental center but extensive occupation. The coastal plain was thus an important part of Late Classic period occupation of the Soconusco and Neff (2014) has documented that the same is true of the nearby estuary.


Blake Michael, Robert M. Rosenswig and Nicholas Waber

2015       Architectural Orientations at Izapa: Lidar Mapping Reveals the Dual Roles of Tacaná Volcano and Winter Solstice Sunrise during the Formative Period. Paper Presented at the 80th Annual Meeting of the Society for American Archaeology, San Francisco.

Clark, John E. and Richard D. Hansen

2001       Architecture of Early Kingship: Comparative Perspectives on the Origins of the Maya Royal Court. In Royal Courts of the Maya, Volume 2: Data and Case Studies, edited by Takeshi Inomata and Stephen D. Houston, pp. 1-45. Westview Press, Colorado.

Clark, John E., and Thomas Lee Jr.

2013       Minor Excavations in Lower Izapa. Papers of the New World Archaeological Foundation, No. 75. Brigham Young University, Provo.

Culebro, C.A.

1939       Chiapas pre-histórico: Su arqueología. Folleto no. 1. Huixtla, Chiapas.

Drucker, Philip

1948       Preliminary Notes on an Archaeological Survey of the Chiapas Coast. Middle American Research Records 1:151–169.

Dutton, Bertha P.

1943       A History of Plumbate Ware. Papers of the School of American Research, Santa Fe.

Ekholm, Susanna M.

1969       Mound 30a and the Preclassic Ceramic Sequence of Izapa, Chiapas, Mexico. Papers of the New World Archaeological Foundation, No. 25. Brigham Young University, Provo.

Gómez Rueda, Hernando

1995       Exploración de Sistemas Hidráulicos en Izapa. In VIII Simposio de Investigaciones Arqueológicas en Guatemala, 1994, pp. 9–18. IDAH, Guatemala City.

1996       Izapa: Organización Espacial de un Centro del Formativo en la Costa Pacífica de Chiapas. In VIII Simposio de Investigaciones Arqueológicas en Guatemala, 1995, pp. 549–563. IDAH, Guatemala City.

Love, Michael W. and Robert M. Rosenswig

2017    The New Normal: Formative Period Cities on the Pacific Coast of Southern Mesoamerica. Cambridge University Press, New York, under review.

Lowe, Gareth W.

1977       The Mixe-Zoque and Competing Neighbors of the Early Lowland Maya. In The Origins of Maya Civilization, edited by Richard E. W. Adams, pp. 197-248. University of New Mexico Press, Albuquerque.

Lowe, Gareth, Susana M. Ekholm, and John E. Clark

2013      Middle and Late Preclassic Izapa: Ceramic Complexes and History, Papers of the New World Archaeological Foundation 73. Brigham Young University, Provo.

Lowe, Gareth W., Thomas A. Lee Jr., and Eduardo M. Espinoza

1982      Izapa: An Introduction to the Ruins and Monuments. Papers of the New World Archaeological Foundation, No. 31, Brigham Young University, Provo.

Navarro-Castillo, Marx

2014       Household Economies: The Production and Consumption of Plumbate at Miguel Alemán, the Conquista Campesina Complex and the Piñuela Complex. Ph.D. dissertation, Department of Anthropology, University at Albany, Albany.

2015       Producción y consumo de cerámica plomiza en Miguel Alemán y los complejos Conquista Campesina y Piñuela, Soconusco, Chiapas. LiminaR Estudios Sociales y Humanísticos 13:102–121.

Neff, Hector

2002       Sources of Raw Material Used in Plumbate Pottery. In Incidents of Archaeology in Central America and Yucatán: Essays in Honor of Edwin M. Shook, edited by Michael W. Love, Marion Popenoe de Hatch, and Hector L. Escobedo, pp. 217–231. University Press of America, Lanham, Maryland.

2003       Analysis of Mesoamerican Plumbate Pottery Surfaces by Laser Ablation-Inductively Coupled Plasma-Mass Spectometry (LA-ICP-MS). Journal of Archaeological Science 30:21–35.

2014       Proyecto Arqueológico Costa del Soconusco. Report submitted to the Consejo de Arqueología, INAH, Mexico City.

Neff, Hector, and Ronald L. Bishop

1988       Plumbate Origins and Development. American Antiquity 53:505–522.

Rosenswig, Robert M.

2008       Prehispanic Settlement in the Cuauhtémoc Region of the Soconusco, Chiapas, MexicoJournal of Field Archaeology 33:389–411.

2016      Olmec Globalization: A Mesoamerican Archipelago of Complexity. In Handbook of Globalization and Archaeology, edited by T. Hodos, pp. 177-193. Routledge, London.

Rosenswig, Robert M., Brendan Culleton, Douglas Kennett, Rosemary Lieske, Rebecca Mendelsohn and Yahaira Nunez-Cortes

2018    The Early Occupation of Izapa: Recent Excavations, New Middle Formative Dating and Ceramic Analyses. Ancient Mesoamerica 29 (1), in press.

Rosenswig, Robert M. and Ricardo López-Torrijos

2017       Lidar Reveals Urbanism across the Entire Ancient Kingdom of Izapa, Mexico. Manuscript under review with Science.

Rosenswig, Robert M., Ricardo López-Torrijos, and Caroline Antonelli

2015       Lidar Data and the Izapa Polity: New Results and Methodological Issues from Tropical MesoamericaArchaeological and Anthropological Sciences 7:487–504.

Rosenswig, Robert M., Ricardo López-Torrijos, Caroline E. Antonelli, and Rebecca R. Mendelsohn

2013       Lidar Mapping and Surface Survey of the Izapa State on the Tropical Piedmont of Chiapas, MexicoJournal of Archaeological Science 40:1493–1507.

Rosenswig, Robert M. and Rebecca R. Mendelsohn

2016    Izapa and the Soconusco Region, Mexico, in the First Millennium A.D. Latin American Antiquity 27 (3): 357-377.

Theses & Dissertations

Mendelsohn, Rebecca R.

2017       Resilience and Interregional Interaction at the Early Mesoamerican City of Izapa: The Formative to Classic Period Transition. Ph.D. dissertation, Department of Anthropology, University at Albany, Albany.

Rebecca's webpage for the Izapa Household Archaeology Project

Navarro-Castillo, Marx

2014       Household Economies: The Production and Consumption of Plumbate at Miguel Alemán, the Conquista Campesina Complex and the Piñuela Complex. Ph.D. dissertation, Department of Anthropology, University at Albany, Albany.

Núñez Cortés, Yahaira

2014    Serving Tortillas and Paying Cacao: An Economic Study of La Libertad site, Late Postclassic Soconusco. M.A. Thesis, Department of Anthropology, University at Albany, Albany.