Sugar pine is most common in Lower Tharp's and upper Log stands. Litter and duff are the predominant ground cover, with scattered herbaceous vegetation. The phenological state of white fir on the site at the time of burning is not given, however, judging from the timing of the fire, it is likely that white fir seeds had been dispersed and the trees were dormant. The study sites comprise the headwater drainages of Tharp's Creek and Log Creek. Soils of both watersheds are predominantly pachic xerumbrepts, derived from granodiorite.
Slopes are moderate to steep.
Areas with heavy fuel concentrations and standing snags burned with the greatest severity. The prescribed burn in the Tharp's Creek watershed resulted in a dramatic rise in mortality rates for 5 years following the fire when compared both with the prefire mortality rates and with the unburned Log Creek watershed. The greatest reduction in white fir numbers was in the intermediate and subcanopy classes. The postfire mortality in the Tharp's Creek watershed was most directly related to fire-caused crown scorch. During the prefire period, the Lower Tharp's stand had a slight decline in total basal area due primarily to the death of numerous codominant and intermediate white fir trees, while the Upper Tharp's stand had an increase in basal area during this period.