Description
The Keystone Site (41 EP 494) is located along the edge of El Paso's Upper Valley, in the path of what was to become the Camino Real trail from Mexico to Santa Fe. During the Archaic period, 4000 years before the appearance of the Spanish, prehistoric Native Americans established a village at the edge of the Rio Grande. The Indians built pit houses with shallow, basin-shaped floors and covered with an igloo-shaped or tipi-like structure of timber and branches, plastered with a thin layer of clay. The people settled close to the river and marsh, gathering wild plants and hunting animals such as rabbits.
The Keystone Dam, which lends its name to the site, was built in 1979-1980 to prevent flooding in the Upper Valley. It was the keystone of the five-dam project that was being built to protect the area on the west side of the mountain from flooding. As required by law, archaeologists were called in to study the site and determine its historical significance. After partial excavation and site mapping in 1979, the design of the dam was altered to avoid covering the ancient village. The Keystone site was determined eligible for the National Register of Historic Places in 1980. It was also designated a State Archeological Landmark in 1983, but portions of the site were subsequently transferred to the Santa Fe Railroad, which planned to build a switching yard there. Much of the land adjacent to the site was swampland, due to the high water table and the natural drainage from the mountain slopes.
The wetland, know locally as Doniphan Marsh, was partially leveled and filled by the railroad company, but their construction plans were thwarted by the Upper Valley Neighborhood Association in 1991, by demonstrating that the marsh was federally protected as officially designated "waters of the United States" under Section 404 of the Clean Water Act. In 1993 a settlement was reached among the Environmental Protection Agency, the City of El Paso, the Santa Fe Railroad, and the U.S. Army Corps of Engineers to protect the wetland. Part of this settlement included the creation of new wetlands in what is now know as Rio Bosque Park in El Paso's Lower Valley. In 1998 the railroad sold the property to CIC Corporation. In December 1999, CIC Corporation donated its portion of the site to the Archaeological Conservancy, so the Keystone site can be managed as a single unit with the City-owned portion of the site
