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Pacific Southwest Region 
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An Assessment of Fuel Treatment Effects on Fire Behavior, Suppression Effectiveness, and Structure Ignition on the Angora FireFire Effects of Non-Treatment AreasDescriptionApproximately 1366 acres within the fire perimeter have had little or no management activity in recent history. Most of this area had little commercial timber value. In addition, there was poor access, or adverse terrain for commercial logging or fire hazard reduction activities. 
Figure 20: Angora SEZ. Dense, continuous stands of trees contributed to rapid spread rates (to the NNE) down this stream corridor. Arrow points in direction of wind and fastest fire spread (NNE). Note greater density of trees within the SEZ (roughly outlined in red). Fire BehaviorBecause of steep terrain and heavy fuel, most of the non-treatment areas burned as a crown fire, consuming 95 -100 percent of the tree crowns and surface vegetation. Areas that did not burn in crown fire, particularly on the southwest perimeter, had sparse fuel. Firefighters on-scene and adjacent homeowners reported that the fire raced down the south portion of the Angora Creek SEZ to the north-northeast and burned up to Angora Ridge to the west as an active crown fire. When the fire entered the meadow portion of the lower Angora Creek SEZ (Figure 20 - the area enclosed by green lines) it changed to a spotty surface fire. The dense stand portion adjacent and to the west of the green rectangle continued to support crown fire runs upslope to Angora Ridge. These dense stands of trees in the Angora SEZ likely contributed to the rapid spread upslope to Angora Ridge and across the slope to the base of Tahoe Mountain. The fire perimeter was contained for two days. However, on June 26 strong winds surfaced causing multiple spot fires to the north of the main fire. Most of this area had not received any management activity during the preceding ten years. Approximately 300 acres burned as a high intensity crown fire between Forest Service Road 12N19 and Highway 89 requiring an evacuation of portions of Gardner Mountain Subdivision. 
Figure 21: Angora Creek SEZ south of Lake Tahoe Boulevard. Note tree density in back of large log. Most surface fuel and tree crowns were consumed by the high intensity fire. Suppression effectiveness, structure ignition, and public safety/egressSuppression resources could not safely engage the fire in most of the untreated areas due to rapid rates of spread and very high intensity. In the southwest portion of the fire, fire crews were able to contain the fire when it reached the rocky ridge top and ran into sparse fuel. The fire was contained in other untreated areas when it ran into an adjacent fuel treatment area, or encountered a change in aspect or topography. There is a small untreated area just below the Angora Highlands Subdivision (see figure 6). Fire intensity and rate of spread were greatest here. One house burned, but it was situated very close to the edge of the steep slope which exposed it to greater convective heat. Firefighters saved many houses here in spite of the intense fire behavior. Contents
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