* The Archaeology of Volcan Mountain *
Fire damage to archaeological sites can be direct or indirect. Direct damage may result from charring and heating; there are many factors involved in whether cultural resources are directly affected by burning (Klemic 2005:43). Fire spalling of boulders can destroy milling and other prehistoric stone features. Archaeologists from the Colorado Desert District, California State Parks, noted extensive damage to bedrock milling features from the 2003 Cedar Fire at Cuyamaca Rancho State Park. Lithic artifacts can also fracture and break under the impact of heat. Recently, Dan Foster, senior archaeologist with CDF, conducted a study to determine the effects of fire on archaeological sites (Waechter 2003). The objective of the study was to evaluate whether a slow-burning or cool fire, such as a prescribed burn, or a fast-burning fire, such as a wildfire, causes more damage to stone artifacts. Surprisingly, the CDF study found that the slow-burning fire resulted in more damaging effects to the artifacts than the hot, fast burning fire. This was credited to the duration of fire exposure; the slow-burning fire exposed the stone to heat over a longer time, and caused more damage. The results of this study have important implications to archaeologists assessing fire impacts.
Indirect impacts to cultural resources as a result of a fire are often more severe than the fire itself. Removal of vegetation by a fire can cause increased erosion and sedimentation, both of which can destroy archaeological sites. Increased visibility of the ground surface can lead to vandalism and unauthorized collection of artifacts. Fire suppression activities such as bulldozer operations can damage sites. Since public and firefighter safety is always a first priority, decisions are sometimes made to proceed with fire suppression activities in areas where archaeological sites are located. However, prior knowledge about the locations of sensitive archaeological resources, and inclusion of cultural resources experts in fire response planning, can help prevent damage and destruction.
Although Volcan Mountain burned during both the 2002 and 2003 fires, most of the sites were undamaged by the fire. This was due to active protection of the mountain by firefighters. The summit road was established as the limit of the fire's reach as it burned up the mountain slope from the east; most of the archaeological sites are on the west side of the summit. For the second time in two years, the sites on Volcan Mountain were spared as a result of firefighter protection of the area.
A notable exception was the Grand homestead, winery, and associated features, located in Arkansas Canyon. The wooden beams and structural components of this stone building were burned, leaving it without adequate support, and the rock structure is slowly collapsing. A round brick oven associated with the Grand homestead was crushed by a burning oak tree, which fell directly onto the feature, destroying it. A conditions assessment by Donaldson (2003) provided a comprehensive evaluation of four structures damaged by the fire. This type of assessment is crucial to identify post-fire damage and develop stabilization recommendations for future action.
Access to the summit of Volcan by firefighting equipment resulted in minimal impacts to archaeological sites in that area. Track marks were observed near only one site (CA-SDI-12922) immediately after the Cedar Fire; by the time of the field visit conducted by the author for this paper (June 30, 2005), these tracks were no longer visible. In fact, the old ranch road that had been used by firefighters has been nearly completely covered by new plant growth since the fire. CA-SDI-12922 was the only site on the summit of Volcan Mountain that was within the burned area, and fortunately the milling features were not damaged.
Volcan Mountain has ongoing issues with dead, dying, and diseased trees. The western slopes of the mountain, which did not burn in either the 2002 or 2003 fires, contain areas that are covered with insect-infested pine trees. These areas pose a future fire hazard. With the high frequency of lightning strikes on the mountain, natural or man-made fires in these areas are inevitable.
Increased accessibility and visibility of archaeological sites is one of the issues that public agencies are confronted with after fires. Dense vegetation often provides protection to sensitive cultural resources; chaparral vegetation provides an excellent cover to hide and protect archaeological resources. After the Pines Fire in 2002, land managing agencies were surprised to see how close trails were to sites that had been invisible before the fire. Many of these hidden sites still have intact surface artifacts that rapidly disappear once they are visible following a fire. Fortunately, if areas can be temporarily closed long enough to allow regrowth of weedy plants, the sites will once again disappear under a thick cloak of vegetation. Periodic monitoring is important, so that if protective measures are necessary, such as trail closure or fencing, these can be implemented before damage occurs.
Public access to Volcan Mountain is limited to a single trail, unless a docent-led walk is underway. Rangers and volunteers monitor the condition of resources on the mountain. Although there has been increased site visibility from the fires, little obvious damage has occurred. Volcan Mountain continues to be an area rich in archaeological resources, where cultural sites are preserved for the future of all Californians.