Center for Desert Archaeology
300 E University Blvd, Suite 230
Tucson, AZ 85705

October 1, 2007

Re: Formal Comments on the I-10 Bypass and its Potential Effects on the San Pedro and Aravaipa Valleys

Dear Mr. Buskirk:

The San Pedro and the Aravaipa drainages are the last relatively pristine valleys in the southern U. S. Southwest. As such they contain near-complete records of 12,000 years of past human activity, both Euro-American and Native American. This scale of regional preservation provides an opportunity to interpret sites as part of a broad cultural and economic landscape rather than as isolated phenomena. The great time depth allows us to study changes in this landscape since humans first inhabited the New World. Such opportunities are no longer available in valleys such as Phoenix, Tucson, and Safford, where early development destroyed much of the archaeological record without adequate documentation.

Considering the non-renewable character of cultural resources, we highly recommend that this landscape be preserved for current and future stakeholders, including Native American groups, archaeologists, and the interested public. Construction of an I-10 bypass through this region would have severe detrimental effects on this landscape. The private development that would inevitably follow such a major new highway would likely be the greatest impact on this area’s cultural resources. The ultimate outcome from these direct and indirect consequences of an I-10 bypass can only be characterized as catastrophic.

The Center for Desert Archaeology and previous researchers have identified over 500 archaeological sites on the terraces above the floodplain in the northern San Pedro valley (Benson to Winkelman). About one third of these sites are associated with architecture and are likely to contain human burials. At least 40 sites were villages inhabited by 75-250 people and associated with large cemetery areas. Many of these villages were occupied for centuries, generating considerable archaeological deposits. While, the information in these locations is very valuable for scientific research, the human burials and the cultural values that these sites represent are of great concern to Native American communities. Previous studies by the Center for Desert Archaeology have established that there are strong historical connections and strong cultural interests in the San Pedro valley by the Hopi Tribe, the Pueblo of Zuni, the Western Apaches of both the San Carlos and White Mountain Apache reservations, and the Tohono O’odham.

It is often useful to take a pragmatic/economic perspective when considering archaeological sites. One way to do this is to make an estimate of what it would cost to recover all of the information that is present in a site, using current archaeological methods. While preparing a conservation easement study in 2001, Center for Desert Archaeology staff estimated that the study of just one of the major villages on the San Pedro would cost nearly $ 2,500,000. This estimate is conservative and could easily be doubled or tripled considering the extended timeline for the I-10 bypass project. Excavation costs for smaller habitation sites would vary considerably depending on size and length of occupation, from $100,000 to over $1,000,000. Considering the high research potential of the uniquely intact San Pedro cultural landscape and the limited amount of previous work in the region, it is likely that fairly large sampling fractions would be appropriate in carrying out a program to mitigate impacts. Hence, the mitigation of cultural resources along one of the proposed routes (e.g., K, D) that runs parallel to the valley could easily cost between 50 and 100 million dollars in 10 to 20 years.

Few archaeological sites have been recorded in the Aravaipa valley and prehistoric population there was probably lower than that of the San Pedro valley. However, very little archaeological investigation has been accomplished in the area and intensive survey would be required if the L-route were ultimately selected as the I-10 bypass corridor. The few recorded sites are large villages with surface masonry architecture; the most visible sites from the surface. Undoubtedly, many smaller settlements and even large pithouse settlements have yet to be discovered in the area considering that Aravaipa Creek would have been a reliable source of water throughout prehistory.

The San Pedro valley still supports viable ranches that would be threatened by an I-10 bypass. The ranchers that are still active along portions of the valley would be forced to leave land that has been in single families for as long as six generations. The Natural Resource Conservation Districts (especially the Winkelman and Redington districts) would be very severely affected by this bypass. Ranching is an important aspect of the historical development of the American West, and ranching is a land use that is compatible with the preservation of cultural and biological resources.

In summary, the San Pedro and Aravaipa valleys are the last well-preserved cultural landscapes in the southern Southwest. There are scientific values, cultural values, and interests of the general public that would all be severely harmed by constructing an I-10 bypass. Considering the tremendous impact (direct and indirect) of any feasible I-10 bypass corridor to this landscape and the high cost to the taxpayer to any program that attempts to mitigate those impacts, the Center of Desert Archaeology strongly recommends that the Arizona Department of Transportation explores alternative routes or solutions that avoid these valleys.

Sincerely,

William H. Doelle, Ph.D.

President and CEO