Overview
Archeological studies and excavations were done over the 360 km Right of Way of the San Miguel – Cuiaba gas pipeline.

The archeological field work of Phase I, which ended on March 2000, identified a total of 58 sites along the ROW, access roads and camps. The majority of the sites (48) were found on the segment 2 (KP 73-215). The archeological excavations were financed by GasOriente Boliviano, in accordance with the statement of agreement of Archeological Protection underwritten with the National Bureau of Archeology and Anthropology (DINAAR in Spanish) of the Ministry of Culture, to comply with protection standards of cultural assets by the Overseas Private Investment Corporation (OPIC).

Field Work
The field work was done by URS/Dames & Moore from August 1999 to September 2000.

The field procedure applied during field work on Phase I included the monitoring of the gas pipeline construction, superficial gathering of artifacts, rapid assessment with shovel test, 1 square meter excavation unit and the mechanical pre-excavation of duct trench.

The Phase II field work included investigations outside the ROW in 14 sites, which according to the Phase I could contain potentially important remnants.

Thanks to the field procedures applied in the Phase II study, a great number of artifacts and many samples were found (such as burned wood and animal bone), for further specialized analysis.

Laboratory Work
The laboratory work started in January 2000 after finalizing Phase I field work. It continued further with the additional artifacts from Phase II field work.

In total, approximately 114.000 artifacts from 58 sites were recovered. The majority were ceramic, most of them fractured (approx.110.000 pieces). The rest of the materials found were lithics (approx. 1.800 pieces), bones (approx. 1.500 pieces), moluscs (approx. 500 pieces). The total weight of the collection was approximately 2.2 tons.

The analysis of the ceramics centered mainly in two aspects of the material: 1) the ceramic material o paste and 2) the shape of the ceramic vase. A total of 27 types of paste were identified. It was determined that the paste was probably of a local manufacture, made within the area of their settlements. One of the shape of the vase was of primary global design, used to prepare and store food and beverage; and an open shape of various sizes used to eat and drink. The decoration was mostly engraved and molded and very rarely painted.

The lithic analysis also covered two aspects: 1) raw material identification, and 2) manufacturing techniques. The raw material of the lithics were very variable and included a diversity of sediments, metamorphic and igneous. The manufacturing techniques included scuffing, polishing and hammering. The tool used was limited to stones forged by scuffing. The lithic artifacts were found more frequently at the central zone were the raw material surface naturally.

Archeological Conclusions
As a result of the protection of the cultural asset implemented by GasOriente Boliviano during the gas pipeline construction, previously unknown pre-Hispanic archeological resources were found.

Chronology: based on the 21 radiocarbon samples obtained for the project, it can be determined that the pre-Hispanic occupation started at least 2.600 years ago and continued till the late pre-Hispanic period. Most of the data obtained belong to the late pre-Hispanic period, indicating that 250 years before the arrival of the Spanish conquistadors, there was a maximum of population.

Economy: the pollen study indicated deforestation associated with intentional burning and yucca planting near the Motacú wetland, approximately in 1240 B.C. This is an evidence of the effect on the environment of the traditional slash and burn agriculture. Also in several sites of the segment 2 there are botanical evidence of planting. The animal bones identified in a dump indicate a possible protein diet of the inhabitants, based on ducks, wild boar, deer and other wild animals.

Ritual practice and burial: in two sites of the project area, 5 human burials were uncovered. They were all of children less that 3 years old intentionally preserved in the interior of ceramic vases. Three of the 5 burials contained only skull fragments, indicating some type of secondary practice or sacrifice. Shaped stones were recovered and also clay ornaments hinting possible ritual ceremonies. The absence of adult burials indicate that a different procedure existed for deceased adults.

Ceramic artifacts: the style and scientific analysis of the found ceramics conveyed the base line for the development of a pre-Hispanic cultural chronology for the area.

Cultural Contribution
The archeological discovery of the project represents an important contribution to the cultural asset of Bolivia, completing a sector of the pre-Hispanic map of the country that lingered unknown till now. Together with other recent projects, these studies resulted in a renewed interest, both public and specialized, in the pre-Hispanic history on the low-lands of Bolivia.

The collection of artifacts and the investigation results should be preserved by specialized organizations and in charge of qualified personnel, in order to allow continuity of the studies initiated with this project. Also it is the best opportunity to extend the information to the general public that may be interested in the pre-Hispanic past of the region.