Twin Lakes

Project name: Twin Lakes
Location: Chuska Valley
Type of sites: Large multicomponent site, logistical camp, early historic Navajo residence
Period: Late Archaic/early Basketmaker II to early historic
Project director: Steven Lakatos

The Twin Lakes Project

At the southwestern limit of the San Juan Basin, the southern Chuska Valley has some of the densest archaeological remains in the state, with evidence of human occupation for over 5,000 years. However, surface indications at the Twin Lakes project, conducted in the southern Chuska Valley of New Mexico, did not prepare OAS archaeologists for the richness of cultural remains they were to find below the surface.

The environment of the region held many attractions for the aceramic agriculturists, sedentary farmers, and pastoral populations who occupied it in succession over that time. A broad alluvial valley, Tohatchi Flats, channels seasonal runoff into numerous small drainages and larger washes or arroyos, creating a setting conducive to floodwater farming and grazing. The numerous mesas, benches, and ridges in the area, aptly named Tse'nahazoh ("earth marked by rocks"), provided suitable materials for building and the manufacture of chipped stone tools. Tucked between high mountains and low-relief settings, this area also offers access to a wide range of biotic resources, making it ideal for transient, subsistence-based societies. Excavations at Twin Lakes

Excavations along US 666 at Twin Lakes resulted in the documentation and collection of 24,145 artifacts and samples, mostly from two sites—LA 32964 and LA 104104. The features at these sites, along with artifact condition, frequency, and distribution, indicate a high level of organization and suggest that this location functioned as a seasonal camp occupied to exploit an agricultural setting.

LA 32964 is a large multicomponent site with surface evidence of a Basketmaker III/early Pueblo I occupation and a Pueblo II/early Pueblo III unit pueblo. An unexpected Basketmaker II logistical camp was represented by 13 features, including processing and storage facilities and a midden. Carbonized remains (Atriplex or Zea mays) from some of these features indicate an occupation starting in the late Archaic/early Basketmaker II period (cal. 930-800 BC) and ending during the late Basketmaker II period (cal. 400-270 BC). Most dated contexts fall between cal. 750 and 400 BC.

On-site processing of cultivars and wild plant species appears to have occurred in the western portion of the site, food preparation in the southeastern portion, and discard of processed material to the east-northeast. Based on pit feature size and volume, extended storage of food surplus was not anticipated, but several cached ground stone tools indicate planned reoccupation.

The patterned disposal of chipping debris indicates that site structure was maintained even though the site was repeatedly occupied. Importantly, the condition and distribution of the lithic artifacts show that reduction strategies focused on the production and maintenance of small bifacial tools from reduced raw material repeatedly transported to this location, indicating that it may have functioned as part of an established settlement regime. In addition, the high number of fragmentary burned and unburned bones recovered from the midden suggests that harvesting and processing of small game animals also occurred there. Few whole, transportable tools such as projectile points or manos were recovered; however, caching of less transportable items such as metates and grinding slabs suggests the inhabitants were biannually mobile and anticipated returning to this location to pursue similar economic endeavors. The patterned feature and artifact distribution signal that this location was probably reoccupied by the same group or a related social group that followed the same processing and disposal patterns, all pointing to a larger seasonally mobile community and maybe the early formation of land-tenure practices.

Surface manifestations at LA 104106 were clear evidence of a Basketmaker III habitation area, yet the size of the main architectural element and the presence of a pre-Bosque Redondo occupation were unexpected. The Basketmaker III component, occupied between AD 620 and 690, was represented by a large pit structure, several smaller satellite structures, extramural features, and a large volume of material culture, likely representing a year-round habitation area. While the contents of smaller structures indicated they served a variety of mundane subsistence activities (storage, cooking, and perhaps sleeping), the size, floor feature array, and artifacts associated with the largest structure (Structure 1) suggest this site may have also have served a specialized function, perhaps related to community integration or ritual healing. The apparent methodological abandonment of Structure 1, combined with a cached "ritual" container, deconsecrated objects recovered from floor features, and regularly spaced supports, leads to the inference that this structure fulfilled functional roles beyond that of a domicile.

Structure 1 was a large (65 sq m of enclosed space), deep, subrectangular pit structure with an associated bench and detached antechamber. Of all the feature types identified (n = 106), sand-filled pits were the most common (n = 52) and clustered in six general areas, including along the north wall and west walls, in front of the vent opening, and north of the central hearth. Interestingly, pairs of the sealed and open sand-filled pits were evenly spaced, which suggests the use of removable objects that had regular form, such as wooden racks or altars. Of particular interest was one sand-filled pit (among the northern cluster) that contained several unique artifacts, including a broken shell pendant, a friable blue-green mineral, abraded pebbles, and obsidian flakes, in addition to a carbonized corn cupule, an unburned juniper cone, and hundreds of unburned goosefoot seeds.

Recovered near the northeast wall and floor of the antechamber was a La Plata Black-on-white seed jar filled with over 150 lithic artifacts, four white stone ornaments, four bone awls, and one piece of marine shell. All were spatially associated with three hammerstones and two fossilized bone tools. The ceramic container was decorated on the interior surface with opposing thunderbird motifs and a fugitive red pigment applied to the exterior. A pollen sample recovered from the interior of the vessel yielded a unique array of native shrubs, economic plants, and herbs. Ethnographic data show that many of these species have medicinal, ceremonial, or decorative applications.

An early historic occupation appears to date to between cal. 1670 and 1860 cal. AD (1σ), prior to the incarceration of Navajos and Apaches at Fort Sumner, New Mexico. Spatial analysis of temporally diagnostic ceramic types, including Pueblo-period white wares, Dinetah Gray, and historic polychrome sherds, was used to isolate the Navajo component and some of the associated material remains. The close spatial patterning of prehistoric partial vessels along with the Dinetah and historic Pueblo ceramics indicates that partial prehistoric ceramic vessels were acquired by and are contemporaneous with the Navajo occupation. The emphasis on ready-made tools was echoed in the lithic assemblage by a high frequency of formal tools with little evidence of tool manufacture. Exploitation of large mammals, artiodactyl species, and domesticated livestock was common. Macrobotanical data indicated that limited amounts of corn were processed and consumed here. Paired features, a living surface, and the faunal and macrobotanical data indicate this area was likely occupied during two consecutive summer seasons. The presence of an expedient structure, formal tools, and partial ceramic vessels, along with limited evidence of agriculture and an emphasis on hunting and domesticated livestock, suggest a summer residence related to herding and farming.