I-10 Twin Peaks Traffic Interchange, Environmental Assessment

Affected Environment and Environmental Impacts October 2005
(NRHP). Reports of major prior studies were reviewed also, including a recently
completed overview prepared for the TRDN Project, which overlaps most of the
records search area. The records search, which encompassed approximately 10.3square-miles,
identified information about 73 prior studies within the search area.
Prior surveys were extensive and encompassed almost 90 percent of the record
search area (9.25 square miles).
The intensive pedestrian archaeological survey encompassed approximately 144
acres of privately owned land. Observational transects at intervals of 20 meters or
less were walked. The survey area was easily traversed and vegetation was sparse,
which facilitated the survey. Approximately 140 acres was field surveyed for
archaeological resources. Approximately 107 acres was previously surveyed.
Thirteen acres within the channelized bed of the Santa Cruz River were not
surveyed and another 5 acres were not surveyed because right-of-entry had not
been acquired from the property owners. The 5 acres within the discontiguous Safe
Routes to School corridor are within areas that were previously surveyed and data
recovery studies had been conducted prior to construction of the modern
residential development that now covers the area. This area was not resurveyed.
In addition to the pedestrian survey, a historic building survey was completed for
all existing properties within the project area. Potential historic-age buildings and
structures were identified from County Assessor records and then field verified.
All 22 parcels on the southwestern side of I-10 were surveyed for historic
buildings and structures. There were no buildings on the northeastern side of I-10.
The PISA prepared for this project was reviewed because that study had examined
aerial photographs dating between 1960 and 2000, maps dating from the late 1960s
to the mid-1970s, and ADOT as-built plans from 1961. Properties constructed
prior to 1960 were field inventoried. These inventories collected information about
location, property type, historic and present use, construction materials,
architectural style, condition, modifications or additions, and other integrity
considerations. The information was used to complete Arizona Historic Property
Inventory forms.
Identification of Cultural Resources
Archeological Sites - Previously Recorded
The 73 previous surveys identified 49 archaeological and historical resources
within the records search area. Thirty-one of these sites reflected the prehistoric
occupation of the region, 15 were from the historic era, and three sites had both
prehistoric and historic components.
The surveys indicated that 14 of the 31 recorded prehistoric sites were habitation
sites, 10 were artifact scatters without features, and the other 7 were artifact
scatters with no identified features. A high percentage of sites appeared to be
villages, which probably reflected the location adjacent to the Santa Cruz River.
One site dated to the Archaic era, and the others to the Hohokam period. Four
village sites were described as mostly or completely destroyed. Data recovery
Interstate 10 Traffic Interchange at
Twin Peaks/Linda Vista
4-67
Project No.: NH-010-D (AIW)
TRACS No.: 10 PM 236 H5838 01D