6 Minutes for Safety — 2009
Fire Behavior Report, 1998
- July 2 to
Evening of July 5
5, 2230 to July 6, 1530
- July 6, 1530
- July 6, 1600
6, 1603 to 1609
- July 6, 1609
- July 6, 1610
- July 6, 1611
- July 6, 1614
6, 1622 to 1830
6, 1830 to July 11
Behavior Associated with the 1994 South Canyon Fire on Storm King Mountain,
Lightning ignited the South Canyon Fire on the afternoon of July 2,
1994. For the next 48 hours, the fire burned downslope in the leaves,
twigs, and cured grasses covering the ground surface. By 1200 on July
4 the fire had burned approximately 3 acres. It continued to spread downslope
through the day on July 5, covering approximately 50 acres by the end
of the day. General fire activity consisted of low intensity downslope
spread with intermittent flareups and short duration upslope runs in the
fire’s interior. The fire remained active through the night covering
approximately 127 acres by morning on July 6.
On July 6 the fire continued to burn downslope through the surface fuels.
At approximately 1520 a dry cold front passed over the area. Winds in
the bottom of the drainage immediately west of the ignition point were
estimated to be from the south (upcanyon) at 30 to 45 miles per hour.
About 1555 several upslope fire runs occurred in the grass and conifers
on the west-facing slope near the southwest corner of the fire’s
interior. Shortly after the crown fire runs, witnesses observed fire in
the bottom of the drainage, directly west of the ridgetop ignition point.
Pushed by the upcanyon winds, the fire in the drainage spread rapidly
north. As this fire spread north and east, fuel, slope, and wind conditions
combined to result in sustained fire spread through the live green Gambel
oak canopy. The fire began burning as a high-inten-sity fast-moving continuous
front. We estimate that the fire moved north up the drainage at about
3 feet per second. Steep slopes and strong west winds triggered frequent
upslope (eastward) fire runs toward the top of the ridge. These upslope
runs spread at 6 to 9 feet per second. A short time later the fire overran
and killed 14 firefighters.
The South Canyon Fire tragically demonstrates the fire behavior that
can occur given the appropriate combination of influencing factors. While
fire behavior during the afternoon of July 6, 1994, can be characterized
as extreme, it was normal and could be expected given the environmental
conditions. Similar alignments of fire environment factors and the resulting
fire behavior are not uncommon. The uncommon and tragic fact associated
with this fire was that 14 firefighters were entrapped and killed by it.
This study focuses on two events: the blowup or transition from surface
fire to a fire burning through the shrub canopy, and the fire behavior
in the area identified as the West Flank that resulted in the deaths of
We identify three major factors that contributed to the blowup on the
afternoon of July 6, 1994. The first was the presence of fire in the bottom
of a steep narrow canyon. Second, strong upcanyon winds pushing the fire
up the canyon and upslope. Third, the fire burning into the green (not
previously underburned) Gambel oak canopy.
We have drawn a number of discussion points from the analysis. Some of
these points will be readily apparent to firefighters. Others may be less
evident. We believe that all are important. They are:
Topography can dramatically influence local wind patterns.
Vegetation and topography can reduce firefighter’s ability
to see a fire or other influencing factors.
Current and past fire behavior often does not indicate the potential
fire behavior that could occur.
The longer a fire burns and the larger it gets the greater the likelihood
of high-intensity fire behavior at some location around the perimeter.
The transition from a slow-spreading, low-intensity fire to a fast-moving,
high-intensity fire often occurs rapidly. This seems to surprise firefighters
most often in live fuels.
Escape route effectiveness should be considered in relation to potential
maximum-intensity fire behavior rather than past or present fire behavior.
The underburned Gambel oak did not contribute to the blowup. It was
significant in that it did not provide a safety zone.
Smoke can significantly reduce the firefighter’s abilities
to sense changes in fire behavior.
Rocky Mountain Research Station
324 25th Street
Ogden, UT 84401
Bret W. Butler is a Research Mechanical Engineer in
the Fire Behavior Research Work Unit at the Rocky Mountain Research
Station’s Intermountain Fire Science Laboratory in Missoula, MT.
His research focuses on fundamental heat and combustion processes in
wildland fire. Applications for his research include fire behavior models,
links between fire behavior and effects, and firefighter safety. He
came to the Forest Service in 1992 after receiving a Ph.D. degree in
mechanical engineering from Brigham Young University, Provo, UT, where
he studied energy transport in particle laden flames.
Roberta A. Bartlette is a Forester at the Intermountain
Fire Sciences Laboratory in Missoula, MT, where she began working in
1968. She has been involved in studies of fuel beds, smoldering combustion,
and fire behavior of both laboratory and wildland fires. Recent work
includes studies in the use of satellite remote sensing to assess fire
potential in wildland vegetation and the use of Geographic Information
Systems to document wildfire growth. She has a B.A. degree in zoology
and an M.S. degree in forestry from the University of Montana.
Larry S. Bradshaw is a Meteorologist for the Fire
Behavior Research Work Unit at the Intermountain Fire Sciences Laboratory
in Missoula, MT. He received a B.S. degree in meteorology from the University
of Utah in 1975. From 1975 to 1992, Larry was with Systems for Environmental
Management, a nonprofit research organization located in Missoula. Since
joining the Forest Service in 1992, he has specialized in the development
and application of climatology to fire management problems and has authored
several nationally available computer programs in the field.
Jack D. Cohen is a Research Physical Scientist for
the Fire Behavior Research Work Unit at the Intermountain Fire Sciences
Laboratory in Missoula, MT. He has worked on wildland fire issues in
Montana, Colorado, California, and Georgia since 1972. His fire research
experience includes prescribed fire, fire danger rating, fire behavior,
and the wildland/urban interface. His operational fire experience includes
firefighting, fire behavior analyst assignments, and prescribed fire
lighting supervision. He has a B.S. degree in forest science from the
University of Montana and an M.S. degree in bioclimatology from Colorado
Patricia L. Andrews is a Research Physical Scientist
in the Fire Behavior Research Work Unit at the Intermountain Fire Sciences
Laboratory in Missoula, MT. She has been a member of the work unit since
1973 and was Project Leader from 1992 to 1996. She was primary developer
of the BEHAVE fire behavior prediction system. Recent work includes
fire growth simulation and analysis of fire danger rating systems. She
has a B.A. degree in mathematics and chemistry from Montana State University
at Billings, and an M.A. degree in mathematics and computer science
from theUniversity of Montana.
Ted Putnam is an Equipment Specialist at the USDA
Forest Service Missoula Technology and Development Center. He started
working for the Forest Service in 1963 and spent 3 years on District
fire crews, 8 years as a smokejumper, and 3 years as a supervisory smokejumper.
He has been working at the Missoula Technology and Development Center
since 1976. In 1977 he received a Ph.D. degree in experimental psychology
with a major in learning and minor in mathematics from the University
of Montana. He is now responsible for developing wildland firefighter
protective clothing, and fire shelters, including training materials,
and has been actively involved in wildland fire entrapment investigations
since 1976. He is a member of two National Fire Protective Association
standards setting committees for protective clothing and equipment.
Richard J. Mangan has been the Fire and Aviation Program
Leader at the USDA Forest Service Missoula Technology and Development
Center since 1989. His major responsibilities include fire equipment
development, wildland firefighter personal protective equipment, and
smokejumper activities. Dick serves on the National Wildfire Coordinating
Group Fire Equipment and Safety and Health working teams, and is chair
of the National Fire Protection Association 1977 Technical Committee
(wildland fire personal protective equipment). He is red-card qualified
as an Operations Section Chief I, and serves as Operations Chief on
a National Type 1 Overhead Team. Dick has a B.S. degree in forestry
from Humboldt State University, and more than 20 years experience on
Ranger Districts and National Forests in Oregon and Washington; his
last assignment before moving to Missoula was as Fire Staff Officer
on the Ochoco National Forest in Prineville, OR.
We authors express our sincere appreciation to the many firefighters
who endured repeated questions regarding often painful memories of the
South Canyon Fire. Those deserving special credit for their patience include
Sonny Archuleta, Sarah Doehring, Kevin Erickson, Dick Good, Eric Hipke,
Dale Longanecker, Tony Petrilli, Michelle Ryerson, Bryan Scholz, Tom Shepard,
and Bill Thomas. Special thanks go to Sue Husari for providing detailed
information about the specific fire behavior. We appreciate the willingness
of author John N. Maclean to share his interview notes with us. We also
acknowledge the contribution of time and effort by the many technical
reviewers and the Ogden Publications Office. Their comments led to a significantly
improved manuscript. Finally, we acknowledge the ultimate sacrifice by
the 14 firefighters who died during the South Canyon Fire. We hope that
information gained from this work will protect the lives of other firefighters
in the future.
reading—Fire Behavior at South Canyon Fire, Preface >>>