Construction Timber Transport to Chaco Canyon: Prehistoric Rolling Roads?

Abstract

The system of long, straight, and wide roadways stretching hundreds of kilometers across northwestern New Mexico is often cited as a singular feature of the prehistoric Chaco culture. The eight-to-ten-meter wide paths have been well identified but the purpose of these roads remains much of a mystery. This paper postulates that the roads were built and used specifically for rolling timbers to construction sites. While the function of timber transport from forest sources to Chacoan building sites has been attributed often to the roads, researchers have invariably assumed that the timbers were carried. The paper presents considerations why a rolling technique for moving logs would have been used, cites its use in other countries, and argues that the case for rolling deserves more attention than has so far been given.

El sistema de largos, rectos y anchos caminos que se extienden por cientos de kilómetros a través del noroeste de Nuevo México es frecuentemente referido como una característica de la cultura Chaco prehistórica. Estos caminos de entre ocho y diez metros de ancho han sido muy bien identificados, pero su función continúa siendo un misterio. Este artículo propone que dichos caminos fueron construidos y usados especialmente para rodar vigas a los sitios de construcción. La función de estos ha sido frecuentemente atribuida al traslado de vigas desde el bosque, hasta los sitios de construcción de Chaco, pero los investigadores que han propuesto esto invariablemente han asumido que dichas vigas fueron cargadas. El artículo presenta consideraciones de porqué se usó una técnica de rodamiento para mover troncos de madera, y como esta ha sido empleada mostrando su valor en otros países, argumentando que esta técnica de rodamiento merece mayor atención que el que se le ha dado hasta el momento.

KEYWORDS:

• Chaco Roads
• Wide Prehistoric Roads
• Timber Transport
• Rolling Logs
• Anasazi Roads

Notes

1 Major long-distance roads depicted are from sources including U.S. National Park Service, U.S. Department of the Interior (1987) and Doyel (2001). Full agreement on “confirmed” road segments has not been reached by researchers. For example, Sofaer et al. (1989) describes the Great North Road as ending at the head of Kutz Canyon; but others (Betancourt et al. 1986; Lekson 2006) contend that the northern roadway continued on to the Salmon Ruins on the San Juan River. Roney (2001) provides a minimum estimate of the extent of the roads.

2 This paper does not argue that wooden “rails” were a Chacoan technique used to help roll construction timbers, but the concept should not remain unexamined. Perhaps the use of small diameter poles as rails offers a prospect for explaining the intriguing grooves that can be seen running linearly down Chacoan roads in several locations where roadbeds are sandstone [for example the 300-meter Coyote Canyon grooves (LA38454) on the southwest road (Nials et. al. 1987:1050)]. The reported depth and width of these carved grooves might be consistent with their use as base for wooden pole “rails” along the lines described by Cermak and Lloyd (1962).

3 On this point, Stuart (2000) speculates that construction of the wide roads resulted from “make-work” projects, but he acknowledges that productive alternatives for labor existed at that time. Further, skeletal evidence has shown extreme malnutrition occurring in the population of Chaco Canyon's “lesser houses” during the period when most construction timbers were transported. During times of hunger in an economy with nutrition based on hunting, gathering, and dry farming augmented by labor-intensive hand and canal irrigation, additional labor hours spent in food production would be expected to have at least some positive value, even if the output was small on the margin. Phillips’ analysis (2009) highlights the point that the requirement for foodstuff production in Chaco Canyon had reached the stage where practice of all of the three basic techniques (irrigation, farming and forage) was required. In his model, a new requirement for construction labor could be thought of as shifting the “calorie production curve” to the left, while any labor-saving changes would act as a welcome shift of the curve back towards the right. What (Phillips 2009:700) notes might apply in the case of Chacoan construction workers:

By understanding the marginal costs and returns for specific approaches, as developed through trial and error, and by basing decisions on that understanding, prehistoric households made choices in the face of cultural and natural constraints. And, by making the choices they did, prehistoric people actively shaped the content of their culture.

4 For his calculations Lekson (1984:281) used the distance from Pueblo Bonito to Lobo Mesa of 48 kilometer. Windes and McKenna (2001:136) note that this distance would almost double for wood taken from the Chuska Mountains, thus substantially increasing the transportation task.

5 As an additional consideration, the narrower “spur” roads that have been found connecting the great houses and kivas within Chaco Canyon are not wide enough for the Snygg and Windes technique of carrying the large beams. These narrow roads may well have been wide enough, however, for rolling these timbers to their construction sites.

6 Lekson (1984:31) describes this as follows:

Wood of this small diameter has a more pronounced taper than larger beams. To equalize this taper, secondaries were often paired with the butt ends in opposite directions. These paired units (or in some roofs, individual secondaries) generally spanned a single pair of primaries, interdigitating with secondaries spanning adjacent primaries. In very small rooms, secondaries occasionally spanned the entire length of the room. …  Secondary beams were usually lashed to each other and presumably to the primaries.

7 Windes and McKenna (2001:133, 136) state:

The time required for the task of binding the lintels together is uncertain. Aside from gathering long leaves of yucca, not local to Chaco, to level the pole sets, and preparing the binding cordage, a skilled craftsperson could finish a lintel prefabrication set in perhaps an hour). These sets, weighing about 9-kg each, could be bound together in groups of 4 to 6 for transportation to the construction site. The similarity of this technique with basket production suggests an intersecting craft technology involving women. Women carried out similar activities in the Northwest Coast cultures involving basketry, rope production, and numerous other activities related to tree by-products.

8 Judd (1954:398) said:

Thousands of logs went into the roofs and ceilings of Pueblo Bonito. Fragments unearthed during the course of our excavations were invariably straight-grained, clean, and smooth. They had been felled and peeled while green; they showed no scars of transportation. Clearly they were cut within easy carrying distance. The character of their annual rings shows that most of them grew under exceptionally favorable conditions … Such regularity indicates an abundant, constant water supply. Obviously Chaco Canyon had more rainfall when those beams were living trees.

9 At that time Judd also reported an earlier account of an elderly Navajo in 1896 saying that his ancestors learned from the Chaco people how big pine beams were hauled to the pueblos “on little wagons whose wheels were cross sections of other logs.” Judd (1954:350)