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LOMA del RIO ARCHAEOLOGICAL SITE

LOCATION
The property is located at 715 North Mill Avenue, on a portion of a 72 acre parcel (132-04-002E) within the 296 acre City of Tempe portion of the 1500 total acre Papago Park.

RELATED DOCUMENTS
Historic Preservation Commission [Staff Report] :: 11 May 2006 

Historic Preservation Commission [Staff Report] :: 8 June 2006 

Planning & Zoning Commission Public Hearing [Staff Report] :: 27 June 2006

RESOURCES
Lynn S. Teague, 2000; The Four Southern Tribes and The Hohokam of The Phoenix Basin
/historicpres/docs/FourSouthernTribesHohokam.pdf

City of Tempe, 2001; Intergovernmental Agreement Respecting Burial Discoveries
/historicpres/docs/IntergovernmentalAgreementRespectingBurialDiscoveries.pdf

Tempe Historical Museum, 2006; Loma del Rio: Prehistory in Papago Park

Archaeological Research Institute, 1999: Pueblo Loma del Rio, an ancient Hohokam site in Tempe Papago Park http://archaeology.asu.edu/vm/southwest/loma/loma_del_rio.htm

Archaeological Research Institute - Arizona State University 480.965.9231
http://archaeology.asu.edu/

David Jacobs and Glen E. Rice, 2002; Hohokam Impacts on the Vegetation of Canal System Two, Phoenix Basin
/historicpres/docs/HohokamImpactsVegetationCanalSystem2.pdf

SUMMARY
HPO recommends Loma del Rio as an excellent candidate for historic designation and listing in the Tempe Historic Property Register. Tempe Papago Park is dedicated to the opportunity for the city dweller to get away from the noise and rush of the urban environment and enjoy contact with nature.4 In addition, Tempe's Papago Park provides an archaeological perspective unique within the Salt River Valley due, in part, to the geographic occurrence of the Tempe and Papago Buttes on opposite sides of the Salt River. The high ground of the Papago Hills represents an island of natural desert in a vast plain of prehistoric irrigated fields. Hohokam (A.D. 500 to 1450) and early Akimel Au-Authm5 (A.D. 1700 to 1850) treated the Papago Park area in a way which was different and unique from their villages spread out over other parts of the valley floor. Loma del Rio provides insight into Hohokam use of non-irrigated fields to raise desert plants. The site indicates use as an Akimel Au-Authm shrine in the protohistoric period. The Loma del Rio site shows a different aspect of Hohokam society; use of the desert in ways not represented at other interpretive facilities.

HISTORY
Loma del Rio (hill by the river) is an archaeological site occupied by the Hohokam during the late Classic Period. Ceramic and lithic evidence recovered from the site indicates occupation between A.D. 1300 and A.D. 1450. Loma del Rio was probably the residence of 15 to 20 people, perhaps an extended family including cousins, aunts and uncles, and several generations of parents. The site contains remains of a block of six connected rooms and one isolated room on the east side thought to have been used for cooking and food processing. Room walls were constructed from stone masonry set in adobe mortar on trenches excavated to bedrock. At some point during occupation, doorways in three of the rooms on the north and west sides were sealed and the rooms were likely used for storage. A cobble bounded, caliche-paved, activity surface or patio separates the roomblock from the single room at the east by 6 to 7 meters. Crescent-shaped agricultural terraces on the hillside southwest of the roomblock complete the inventory of structures at the site. The crescent-shaped agricultural terraces built into the hillside were ideal for growing agave (aka the Century Plant), which requires no irrigation. Agave grown at Loma del Rio may have been consumed on site and traded with local villages. Besides local agave trading, evidence of trade between Loma del Rio and people as far as 300 miles away was found at the site. Archaeologists determined this by distinctive pottery and stone tool fragments found at the site which appear to have come from such places as Casas Grandes, Mexico; Mule Creek, New Mexico; and Flagstaff, Arizona. In fields below the terraces, crops such as corn, beans, and squash could have been grown in the floodplain of the Salt River, and certainly flora and fauna native to this riverine habitat were exploited by the occupants of Loma del Rio.

In 1887, Frank Hamilton Cushing led the first archaeological expedition to the Salt River Valley. He established a base camp on the north bank of the river near where the ASU Community Service Building is now located. In 1887, Cushing identified the Loma del Rio site as “Los Pueblos Arriba” (Haury 1945:189) and reported evidence of use as an Akimel Au-Authm shrine during the protohistoric period. Cushing collected Casa Grande Red-on-buff sherds, Gila Polychrome sherds, projectile points and other artifacts from Loma del Rio. He reported the presence of “a little Pima shrine, not very recent, nor yet exceedingly ancient, consisting of a terraced alter built up of loose stones that had fallen from the walls, on a step of which were numerously displayed a bunch of arrows with hard-wood, sharpened foreshafts, all neatly laid, somewhat fan-shaped, and held in place by two large flattened stones. In the midst of these were a few scattered beads, mostly of blue glass, but some white and two or three red.”

In 1928, Gila Pueblo archaeological staff (possibly including Frank Midvale; a member of this group who was living in Phoenix at this time) surveyed the Loma del Rio site. Established by Harold S. Gladwin and Winifred Jones MacCurdy (Gladwin) in 1928 as a private archeological research institute, the Gila Pueblo Archaeological Foundation first defined and then detailed the Hohokam archaeological tradition. In 1928, Gila Pueblo identified the Loma del Rio site as Mesa 1-6 (GP) and plotted it on Gila Pueblo map 023709. The site was described as a seven room stone pueblo, possibly of two stories, covering about 150 by 150 yards. The walls were noted to average 18 inches thick composed of horizontal stone with adobe in the cracks. Although past efforts to locate documents pertaining to Gila Pueblo activities at the site have not succeeded, evidence indicates Gila Pueblo conducted excavations within two or more rooms at Loma del Rio. Book 6 of the Midvale collections at the ASU Department of Anthropology provides a site plan map and photographs the Loma del Rio site identified as “El Pueblito” or the “Stone Ruin”. Midvale’s notes indicate circa 1931, he collected 100 sherds from the site; 62 redware (36 with burnished interiors and the remainder with plain interiors), 38 plainware, and 2 Gila Polychrome.

In 1939, prominent archaeologists Odd S. Halseth, Albert H. Schroeder and Julian T. Hayden recorded the Loma del Rio archaeological site together as part of Schroeder’s survey #22. Halseth and Hayden had worked with the Civilian Conservation Corps and Schroeder with the Works Progress Administration. The 1930s witnessed a new kind of large-scale archeological project as part of federal unemployment relief projects and programs funded by the Works Progress Administration and other public employment programs of the New Deal. In order to employ large numbers of people affected by the depressed economy, archeological projects of this decade focused on fieldwork and on keeping large crews fruitfully employed in excavating archeological sites. Unfortunate consequences of many of these projects were delays in the production of descriptive reports, delays in data analysis, and little publication of project results. Despite these drawbacks, the programs resulted in a substantial increase in knowledge about American archaeology, especially in the Southeast. In 1939, Schroeder, Halseth, and Hayden identified the Loma del Rio site as AZ U:9:14 (PG) and estimated that Civano sherds accounted for 68% of the ceramic assemblage with the remainder dating to the Soho phase. Field notes indicate the site was still in a good state of preservation at this point and relatively free from post-occupational disturbance.

In the 1960s, after prolonged neglect and vandalism, the Loma del Rio site again became the focus of scientific interest. In 1961, the site was visited by Dr. Donald H. Morris and Frank Midvale. Although no collections were made in 1961, Morris and Midvale identified the site as Loma del Rio, completed and ASU Archaeological Survey Form with a sketch map, and noted the site had been heavily impacted by pot hunters. Soon after, 59 sherds were collected from the site and recorded on an ASU Cultural Inventory Methods class specimen log sheet. In 1964, Arizona State Museum personnel surveyed Loma del Rio and identified the site as AZ U:9:10 (ASM). They also reported the site was badly pot hunted with some rooms excavated to a depth of 1.5 meters. ASM collected one box of materials including Classic period redwares.

By the 1970s, Loma del Rio had come to the attention of ASU. In 1973, Betina Rosenberg and Donald E. Weaver, Jr. surveyed the site, and identified the Loma del Rio site as AZ U:9:24 (ASU), the designation used for all subsequent site activities. In 1977, Dr. Alfred E. Dittert, Jr. and ten graduate students from his ASU Cultural Inventory Methods class assessed archaeological resources within the Rio Salado Developmental District and identified interpretive opportunities at Loma del Rio.

From 1984 to 1986, Arizona State University archaeology students under the supervision of Dr. Dittert carried out various excavations at the site. In 1988, Loma del Rio was part of an archaeological survey of a 40-acre area of Tempe Papago Park. Commissioned by the City of Tempe, ASU produced a document titled “A Plan for the Management of Archaeological Sites in the Tempe Papago Park Area” prepared for the city by Linda Williams and Karen Atwell, Office of Cultural Resource Management, Department of Anthropology, Arizona State University.

In 1991, the Arizona Parks Board awarded a Heritage Fund historic preservation grant to the City of Tempe for stabilization of the Loma del Rio site. From 1993 through 1995, the site was stabilized by the City of Tempe in partnership with Arizona State Parks; Dr. Amy Douglass Tempe Historical Museum Administrator (project conception and realization), Dr. Glen Rice and the ASU Office of Cultural Resource Management (field work), National Park Service (technical assistance with stabilization), Dr. Dittert (expertise on the Hohokam and information regarding prior excavation of the site), Howard Needles Tammen & Bergendoff (HNTB), Architects, Arizona State Parks and the State Historic Preservation Office (Heritage Fund grant).

On October 14, 1995, the Loma del Rio Archaeological Site was dedicated by the City of Tempe as part of the Rio Salado Expo that included dedication of Papago Park Trails and Rio Salado Project Update presentations. Today, this 650 year old archaeological site has been stabilized and is easily accessible to the public. A shade ramada and a wheelchair accessible path add to the comfort of visitors who explore the ruin along an interpretive trail. Special plaques inform visitors of the unique characteristics of the site.

DESCRIPTION
Loma del Rio ("hill by the river") is located on the crest of a ridge on the north side of the Rio Salado. This archaeological site includes a Hohokam ruin that is approximately 650 years old and is easily accessible to the public. Stabilized and enhanced with a ramada and wheelchair accessible path, visitors may explore the ruin at no cost.

Loma del Rio was a small Hohokam residence that was occupied during the Classic Period, some time between A.D. 1200 and 1450. The site might have been home to 15 or 20 people belonging to an extended family. Several generations of parents, grandparents, siblings, aunts, uncles and cousins probably lived together. The site contains the remains of a block of six rooms, an isolated room, a stone-paved area and agricultural terraces on the slope of the hill immediately to the southwest of the habitation. The single room on the east side appears to have been used for cooking and processing food. The remaining six rooms were built as residences. However, some time during the occupation of the site, the doors of three of the rooms on the north and west side of the room block were sealed off, probably so they could be used for storage. They would have been entered from an opening in the roof. The concentration of rocks on the southeast side of the site appears to form the surface of an open area that was used for a variety of domestic activities. The site at one time may have also contained a walled plaza.

INTEGRITY
The adobe walls of Loma del Rio were covered in 1994 in order to minimize further erosion and deterioration. In 1928, archaeologists estimated that the partially buried walls were at least six feet high. Today, the walls are no more than three feet high and have collapsed in many places. If left exposed, the site would have faded completely into the landscape. There is no effective means of treating the adobe to stop deterioration. Covering the structure will preserve what remains for future generations. The walls can be uncovered for further study or in the event that a technique is developed to preserve and stabilize adobe.

Loma del Rio was last excavated in 1984 and 1985 by archaeologists from Arizona State University. After the excavation was completed, plastic sheeting and soil were placed over the site. These materials have been left in place. When the stabilization began in 1994, a special synthetic textile was placed over the existing surface to provide a moisture-resistant layer while allowing air to circulate through the soil. The mound was built layer upon layer using soil similar in chemical composition to the natural terrain. Each layer was compacted to minimize erosion and the surface of the mound was graded to provide runoff. Historic photographs were used to make the mound look much as it did before it was excavated. In the last decade, natural vegetation has grown over the mound, holding the soil in place and further minimizing erosion.

SIGNIFICANCE
Loma del Rio is significant as one of the first two sites where sherd tempering in Hohokam ceramics has been detected. Classification of prehistoric ceramics according to their stylistic and technological characteristics has been an important component of southwestern archaeological research since its inception. Ceramics are used to define prehistoric cultural units, delineate their boundaries, and identify their chronological sequence. Untempered clay used in ceramic production will shrink and crack during drying or firing. To alleviate this, various forms of temper were added to the clay to provide greater strength. Crushed rock was frequently employed for this purpose. Increasingly during the late Classic period, old broken pottery was crushed and added to the clay as temper, providing an additional diagnostic ceramic attribute. Sherd tempering appears to be limited to redwares at Loma de Rio, indicating early application of this method in the temporal ceramic sequence.

Loma del Rio is significant because of the use of stone cobble as a core for adobe wall construction. The walls of the rooms at Loma del Rio were constructed by forming adobe around a core of stones. The stones were taken from the local bedrock formation. The adobe was made by mixing clay from the river banks with water. Wooden forms may have been placed on either side of the stone core in order to build up the adobe walls. The surfaces of the walls may have been plastered with caliche, a hard-packed soil that contains high concentrations of lime (calcium carbonate). While this construction method is seen in other areas, it is uncommon in the Phoenix Basin.

There is evidence for a network of crescent-shaped terrace gardens built into the hillside to the west and south of the roomblock. In addition to irrigation agriculture, Hohokam farmers also built hillside terraces to contain small amounts of rain. These terraces were ideal for growing agave, also known as the century plant, because agave plants required very little water. Agave was an important food source, especially during periods of drought. The Hohokam ate the nutritious heart of the agave and used the fibers from the leaves to weave cloth or make rope. It is possible that they traded some of the agave with other villages for items that they might have needed. Other crops such as corn, beans and squash could have been planted below in fields irrigated by water from the Salt River.

Loma del Rio is a significant site on many levels. From a recreation and tourism standpoint the site enhances the City of Tempe’s park system. Having an archaeological site in an urban setting allows easy accessibility to tourists and residents alike. From an archaeological standpoint, it is important to understanding Tempe and the Valley of the Sun’s past as it relates to Hohokam occupation for approximately 1500 years. Small farmsteads are relatively rare in the metropolitan area, and most interpretive efforts have gone into large towns/sites such as Pueblo Grande. Loma del Rio gives us a glimpse at life in a small settlement where farming terraces rarely found in the center of the Salt River Valley occur much as they do further out at higher elevations. Archaeological sites give us more information on how the Valley of the Sun was populated, the location of settlements, and how they interacted with one another.

Loma del Rio is also significant by association with a number of prominent archaeologists of their period including; Cushing, Hayden, Halseth, Midvale, and Schroader. The longevity of the time period that is represented (1890s to 1930s+) reinforces the site’s significance to the history of Hohokam archaeology.

RECOMMENDATIONS
Staff recommends that the Tempe Historic Preservation Commission support the nomination for historic designation and listing in the Tempe Historic Property Register for the Loma del Rio Archaeological Site AZ U:9:24 (ASU) HPO-2006.40 ORD# 2006.43, and that Tempe HPC direct Staff to assist in this regard. The basis for this recommendation is that the Loma del Rio Archaeological Site AZ U:9:24 (ASU) has yielded information important in prehistory.

Staff recommends that the site boundary for purposes of historic designation of AZ U:9:24 (ASU) be that identified as Assessor’s Parcel Number 132-04-002E, a 72 acre parcel that includes samples of related ecosystems along with the habitation locus and terrace garden network at AZ U:9:24 (ASU).

Last updated: 5/9/2012 9:17:40 AM