The 2002 fire season was one of the biggest of the past half-century. By the end of the year, fires had burned across 7.2 million acres, costing over $1 billion to fight. Almost uniformly, the fires of 2002 were characterized as catastrophic, but in fact, each fire was unique in character, offering individual lessons for the future. The following fact sheet is one of five analyses prepared by The Wilderness Society to better understand the causes and consequences of major 2002 wildfires.
Quick Facts
Location: Southern California. 12 miles north of Kernville, CA.
Cause: Human.
Area within fire perimeter: 150,670 acres.
Structures lost: 14.
Ownership: Sequoia and Inyo National Forests, including about 5% of Giant Sequoia National Monument.
Landscape: Mixed conifer, heavy brush, grass, and fir stands.
Suppression Cost: $45.7 million approximately. |
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The McNally fire started in the early afternoon on Sunday, July 21, 2002 from careless use of fire near the Roads End Resort within the Kern Canyon. The fire spread rapidly within the Kern Canyon to threaten the communities of Johnsondale, Ponderosa, and small subdivisions on private land. In subsequent days, the fire would burn to within one mile of the Packsaddle Grove of giant sequoia within the Giant Sequoia National Monument and enter both the Domeland and Golden Trout Wildernesses.
On two fronts, south and southeast, the McNally fire's advance ended at the site of two previous wildfires -- the 1990 Stormy Fire and the 2000 Manter Fire, respectively.
The McNally Fire burned mostly in brush and open forest
The fire began in brushy vegetation, spreading into oak woodland and, eventually, Sierra Nevada forest. Throughout the fire, daily reports from firefighters repeatedly referred to "heavy brush and mixed conifer" as the fuel. In that part of California, vegetation is dominated by blue oak, interior live oak, gray pine, and various species of ceanothus, and manzanita, all of which are well adapted to fire. As the fire burned upslope, it eventually encountered ponderosa pine and mixed conifer forests, including sugar pine, incense cedar, and white fir, which tolerate surface fire but are killed by crown fire.
McNally did little damage to Giant Sequoia National Monument
Giant Sequoia National Monument is home to nearly half of the remaining stands of the stately trees. The giant sequoia groves have experienced wildfire throughout their long history and have evolved to depend on periodic wildfire. Not only are the massive trees one of the most fire-resistant conifers in the world, their regeneration is dependent on fire. Recent research suggests that giant sequoia seeds grow best where intense fire creates bare soil and canopy openings. Thus, the survival of the species is linked to a mixture of small, severe blazes and frequent widespread surface fires. A century of fire exclusion has resulted in unnaturally dense forests which now threaten to carry unnaturally large and lethal fire into the sequoia canopy.
The McNally fire burned only five percent of the Giant Sequoia National Monument, coming within a mile of one grove but apparently never harming any of the big trees. In addition, according to a post-fire evaluation by the Forest Service, all burned areas were downslope of the groves, so no direct or indirect hydrological effects on the groves are expected from the burn.
The McNally fire largely burned with low severity
According to the McNally fire Burned Area Emergency Rehabilitation (BAER) Plan, less than 9% of the total acres within the burn perimeter are categorized as high burn severity. Over half of the acres did not burn at all or burned with a low severity.
Weather, fuels, and topography all contributed to the fire’s rapid early spread
The first days of the fire saw exponential growth, as the fire increased from 500 acres on its Sunday start to over 48,000 acres by Wednesday, four days later. By the following Wednesday, July 31st, the fire grew to 55% of its eventual size.
During this timeframe, the mountain areas of Southern California experienced daytime highs in the upper 80s to low 90s and the Southern California area was under very high to extreme fire indices. The National Interagency Coordination Center noted unstable weather conditions and erratic winds contributing to the rapid rates of spread.1
In addition, the McNally fire started in a steep canyon dominated by heavy brush. These conditions, combined with extreme weather, made control impossible and contributed to the fire's rapid early spread.
Erosion impacts of the fire may be exacerbated by previous ORV use
Within the area burned in Giant Sequoia Monument, managers are concerned about the Dry Creek drainage, where former ORV trails remain barren. These trails channel water and sediment into Dry Meadow Creek, which supports an introduced trout fishery. The fire burned intensely in this area, and the cumulative effects of pre-Monument ORV use, burned slopes, and heavy November rains have increased sedimentation into the creek.
For More Information
Footnotes
- Archived Daily Incident Management Reports (http://stone.cidi.org)
