South Canyon Fire
1994

William Teie Report to OSHA — 1994

6 Minutes for Safety — 2009

• July 3rd

• July 4th

• July 5th

• July 6th

Fire Behavior Report, 1998

Cover & Dedication

Executive Summary & About the Authors

Preface & Contents

Introduction

Fire Behavior Overview

Fire Environment

• Topography
• Fuels
• Weather

Fire Chronology

• July 2 to Evening of July 5
• July 5, 2230 to July 6, 1530
• July 6, 1530 to 1600
• July 6, 1600 to 1603
• July 6, 1603 to 1609
• July 6, 1609 to 1610
• July 6, 1610 to 1611
• July 6, 1611 to 1614
• July 6, 1614 to 1623
• July 6, 1622 to 1830
• July 6, 1830 to July 11

Fire Behavior Discussion

• Fire in South End of West Drainage
• Winds Push Fire into Bowl
• Fire Transitions to Gambel Oak Canopy
• Fire on West Flank

Conclusions

References

Appendix A

Appendix B

Appendix C

Report of the South Canyon Fire Accident Investigation Team, August 17, 1994

Fire Environment

Fuels

Vegetation in the area consisted primarily of Gambel oak (Quercus gambelii) on the north- and west-facing slopes and open, mixed pinyon-juniper (Pinus edulis and Juniperus sp.) with a cured grass understory on the south-, southwest-, and east-facing slopes. A few “pockets” of Douglas-fir (Pseudotsuga menziesii) existed in the area of the Double Draws, the Bowl, and on the lower east-facing slope of the West Drainage. Continuous cured grasses and some shrubs and small stands of pinyon-juniper covered the bottom of the north-south oriented West Drainage (Anon 1994). The Bowl contained a heavier concentration of grasses, mixed shrubs, woody debris, and trees. Figure 9 shows the approximate distribution of the vegetation over the fire site.

The Gambel oak was more than 50 years old and did not contain much dead material (South Canyon Report; Biastoch 1995). It formed a dense, green, continuous closed canopy, 6 to 12 feet tall and appeared to be unaffected by spring frosts (fig. 10). Visibility within the stand was limited. The surface fuels beneath the canopy consisted of a 3 to 6 inch layer of leaf litter (Husari 1996).

Figure 9—Drawing showing approximate distribution of vegetation in area of South Canyon Fire. Perspective is looking northeast across West Drainage from location over Colorado River (adapted from Accident Investigation Report, not to scale).

Fine dead fuel moisture content was estimated to range from 2 to 5 percent on the afternoon of July 6 (South Canyon Report). Both the large diameter(1000 hour) dead fuels and the live fuel moisture contents in the area were several weeks ahead of their historical summer drying trends (South Canyon Report). No fuel moisture content samples were collected at the time of the fire. However, live foliar moisture contents were measured on July 12, 1994, at a site near the South Canyon Fire with an aspect and elevation similar to the west flank of the Main Ridge. Foliar moisture in underburned Gambel oak was about 60 percent while that in green unburned Gambel oak was 125 percent (South Canyon Report). Typically, live fuel moisture levels change relatively slowly in undamaged shrubs. Therefore, we expect the foliar moisture content of the unburned Gambel oak on July 6 would have been similar to the values measured on July 12. No samples were collected in the pinyon-juniper fuels.

Figure 10—Photograph of Gambel oak at South Canyon Fire Site taken on July 6, 1994. Note lack of significant amount of dead leaves and stems in the canopy. Courtesy of T. Petrilli

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