Yellowstone Handbook 2019


brochure Yellowstone Handbook 2019 - Fire

Yellowstone Resources and Issues Handbook. Published by the National Park Service (NPS).

Fire Fire has been a key factor in shaping the ecology of the Greater Yellowstone Ecosystem. Native plant species evolved adaptations so they survive and, in some cases, flourish after periodic fires. Fire influences ecosystem processes and patterns, such as nutrient cycling and plant community composition and structure. Fire regimes in the western United States changed with the arrival of European and American settlers, whose livestock removed grassy fuels that carried fires and whose roads fragmented the continuity of fire-carrying fuels. Most naturally occurring fires were suppressed to the extent possible. The National Park Service aims to restore fire’s role as a natural process in parks when and where this is feasible. Lightning may ignite dozens of forest fires during a single summer, but most of them go out naturally after burning less than half an acre. Others torch isolated or small groups of trees, become smoldering ground fires, and eventually go out on their own. On rare occasions, wind-driven fires have burned through large areas of forest, as in 1988, when multiple fires crossed more than one million acres in Yellowstone and on surrounding federal lands despite massive efforts to extinguish them. Without frequent small and occasional large fires to create a mosaic of plant communities in different growth stages, biodiversity declines and leaf litter and deadfall accumulate much faster than they can return nutrients to the soil through decay. FREQUENTLY ASKED QUESTIONS: How does fire benefit Yellowstone? Fires are a natural part of the Greater Yellowstone Ecosystem. Vegetation has adapted to fire and, in some cases, may be dependent on it. Fire promotes habitat diversity by removing the forest overstory, allowing different plant communities to become established, and preventing trees from becoming established in grassland. Fire increases the rate that nutrients become available to plants by rapidly releasing them from wood and forest litter and by hastening the weathering of soil minerals. This is especially important in a cold and dry climate like Yellowstone’s, where decomposition rates are slower than in more hot and humid areas. Additionally, natural fires provide an opportunity for scientists to study the effects of fire on an ecosystem. Why aren’t burned trees removed? Burned trees and those that have died for other reasons still contribute to the ecosystem. For example, dead standing trees provide nesting cavities for many types of animals; fallen trees provide food and shelter for animals and nutrients for the soil. However, park managers will remove dead or burned trees that pose safety hazards along roads or in developed areas. Evidence of fires that burned before the park was established in 1872 can be found in soil profiles, charcoal found in lake sediments, landslides, and old-growth trees. Research shows large fires have been occurring in Yellowstone since forests became established following the last glacial retreat 14,000 years ago. Yellowstone’s fire season typically lasts Fire 161 FI RE Greater Yellowstone is a fire-adapted ecosystem. Smoke may be visible from ongoing fires during the fire season, typically mid-June through September. FI RE from July to the end of September. The number and extent of fires that occur each year depend on climate and what efforts are made to suppress the fires, as well as weather conditions such as the number and timing of lightning storms and the amount and timing of precipitation. 1988 1989-2018 1988 and again since Burned areas in Yellowstone from 1988 to 2018. Until 2016, the large fires of the 2000s were burning in areas largely unaffected by the 1988 fires. In 2016 alone, 42,425 acres burned in 1988 fire scars. Ignition Afternoon thunderstorms that release little precipitation occur frequently in the northern Rockies. Yellowstone receives thousands of lightning strikes in a typical summer, but most do not result in fires. A snag may smolder for several days and then burn out because fuels are too moist to sustain combustion or too sparse to permit the fire to spread. The park’s forests have few shrubs; understory fuels are predominantly young trees. The moisture content of both live and dead vegetation tends to drop as summer progresses, temperatures increase, and relative humidity decreases. Fuels have often dried out enough to ignite the first wildfire of the year by mid-July. A forested area that has burned recently enough to contain only young stands of trees usually doesn’t have enough combustible fuel to carry a fire, except under extreme climate conditions. But as the years pass, trees that don’t survive the competition for light and other resources die and eventually fall over. On living trees, older branches die and fall off as they are shaded by new foliage growing above. As a stand grows older and taller, the canopy becomes more broken. This allows enough light to reach the forest floor for a shade-tolerant understory to be established. The accumulation of fuel on the forest floor and the continuity of fuels among the ground, understory, and canopy make older stands more vulnerable to fire. Some forests in Yellowstone may not have burned in at least 300 years and may be particularly prone to lightning ignition. Quick Facts Numbers in Yellowstone • In 2018, 1,764 acres burned from 8 known wildfire starts. One humancaused fire (unattended campfire) was suppressed. Two lightningcaused fires were suppressed due to dangerous conditions. Five fires were monitored for public safety, while fulfilling their role in the ecosystem. 162 • Since 1988, the number of fires has ranged from 1 to 78 each year. • The most active fire year since 1988 was 2016, with 70,285 acres in Yellowstone burned. • In an average year, approximately 21 fires are ignited in Yellowstone by lightning. • About 75% of fires in Yellowstone never reach more than 0.1 hectares (0.25 acres) in size. • About 92% of fires in Yellowstone never burn more than 40 hectares (100 acres). Characteristics • Yellowstone’s landscape has been shaped by naturally caused fire for 14,000 years. • Factors affecting size and severity of a fire include: type of vegetation; fire location; time since the last stand-replacing fire; moisture in the dead and down logs; length of drought; temperature; humidity; and wind. Yellowstone Resources and Issues Handbook, 2019 • In Yellowstone, on average, fires are detected at 3:03 in the afternoon—fires burn most vigorously during the heat of the day, causing tall smoke plumes to be seen by fire lookouts or sharpeyed park visitors. Management Issues • The park is required to protect human life as well as the approximately 2% of Yellowstone’s 2.2 million acres that are considered developed (e.g., roads, buildings, and other infrastructure) from the threat of fire—while at the same time letting fire carry out its ecological role in the landscape as much as possible. Fire Behavior Of the fires that occur in Yellowstone National Park, 75% are less than 0.2 acres and another 13% range from 0.3 to 9.9 acres. These smaller, less intense fires play a role in this ecosystem by helping to thin out smaller trees and brush and boost the decay process that provides nutrients to the soil. Some fires burn with extreme fire behavior and rapid rates of spread. These large, fast-moving fires send plumes of smoke thousands of feet into the air and receive much of the public’s attention. These large fires (>100 acres) occur less than 10% of the time in the park. Fire 163 FI RE Nearly all of Yellowstone’s plant communities have burned at one time or another, but their varied characteristics cause fires to behave differently in them. To quickly assess a fire start and its potential to spread, park staff use different vegetation communities as indicators of fuel load, dominant vegetation, and time since the last fire or other disturbance. The moisture content of dead and downed woody debris and the year’s weather trends are the main factors determining the severity of a given fire season. While fires can occur no matter the fuel moisture, many times conditions are too wet for fires to burn. In fact, 88% of all fires burn fewer than 10 acres. However, when 1,000-hour fuel moistures fall below 13%, fires can grow quickly. If extreme drought continues, all forest types and ages are more likely to burn. To determine how much water is in the fuel, Yellowstone fire-monitoring staff weigh and ovendry fuel samples to determine the moisture content. In a normal fire season, 1,000-hour fuels within the park may average 14–18% fuel moisture. (Dead fuels are classified according to size, and how long they take to dry out when completely soaked; “1,000-hour fuel moisture” refers to the moisture in large fuels such as downed timber that would generally dry out within 42 days. Kiln-dried lumber is 12%.) Active fire behavior is generally not observed until 1,000-hour fuel moisture contents are less than 18%, and only minimal areas are burned until moisture levels drop to 13%. At that point, a fuel-moisture threshold is crossed; lightning strikes in forested areas at 13% fuel moisture quickly result in observable smoke columns and, if fuel and vegetation conditions are right, the fire spreads. Below 12%, younger and more varied forest types burn readily, especially when influenced by high winds. During extreme drought years, 1,000-hour fuel moistures may drop as low as 5%. Depending on the forest type, fuel moisture, weather, and topography, fires can grow in size by isolated or frequent torching and spotting (transport of burning material by wind and convection currents), or by spreading from tree crown to crown. Fires in Yellowstone’s subalpine forests seldom spread significantly through ground fuels only. Like weather, terrain can be either an ally or adversary in suppressing unwanted fire. A few natural barriers such as the ridge from Electric Peak south to Mt. Holmes; Yellowstone Lake; and the Absaroka Mountains along the eastern boundary of the park are likely to prevent the spread of a low-to-moderateintensity fire, but fire may cross these features by spotting, covering a distance of two to three miles. Fire managers may be able to predict a fire’s behavior when they know where the fire is burning (vegetation, topography) and the fuel-moisture content. However, predicting fire is much more difficult during extreme drought, such as was experienced in 1988 and in the early 2000s. Ongoing research in Yellowstone is also showing that forests experiencing stand-replacing fires can affect fire behavior for up to 200 years. When a fire encounters a previously burned forest, its intensity and rate of spread decrease, except under extreme drought conditions. In some cases, the fire moves entirely around the burned area. Thus, fire managers have another tool for predicting fire behavior: They can compare maps of previous fires with a current fire’s location to predict its intensity and spread. FI RE Frequency of Fire Fire return intervals since European American settlement have ranged from 20–25 years for shrub and grasslands on the northern range to 300 years or more for lodgepole pine forests on the central plateau and subalpine whitebark pine stands. Fire scars on old Douglas-fir trees in the Lamar River valley indicate an average frequency of one fire every 25–60 years. Until 1900, written records on fires in Yellowstone were sketchy, with generally only large fires reported. From 1900 through 1930, approximately 374 fires burned 11,670 acres. Since 1931, when fire statistics began to be kept more methodically, 1,644 fires have been lightning-caused and 740 were considered human-caused, including those caused by power lines. The largest fire in the park’s written history prior to 1988 occurred when about 18,000 acres burned at Heart Lake in 1931. In 1989, fire ecologists William Romme and Don Despain suggested that without the fire suppression efforts that began in the 1880s, large fires might have occurred during the dry summers of 1949, 1953, 1960, or 1961. They believe that fire behavior in 1988, in terms of heat release, flame height, and rate of spread, was probably similar to that of the large fires that burned in Yellowstone in the early- to mid-1700s. In 1988, 50 fires burned a mosaic covering about 800,000 acres in Yellowstone as a result of extremely warm, dry, and windy weather combined with an extensive forest cover of highly flammable fuels. Some of the largest fires originated outside the park, and a total of about 1.4 million acres burned in the Greater Yellowstone Ecosystem. Some of the areas that burned in 1988 have burned again during the drought conditions of subsequent years, although unique conditions are required for such areas to reburn. Rare, extremely high wind events (greater than 20 mph), more than 80% ground cover of cured elk sedge (Carex spp.), or a continuous fuel bed of 1000-hour logs during very dry conditions, seem required for fires to again 164 Yellowstone Resources and Issues Handbook, 2019 carry through areas burned in 1988. Fire behavior of previously burned areas is generally of a very high intensity—probably because of the high fuel load due to dead and fallen trees. Understanding the conditions necessary for recently burned areas (less than 50 years old) to reburn and modeling for the type of fire behavior seen in these areas is a current challenge for fire managers in Yellowstone. Consequences of Fire In the first years after a major fire, new vistas appear while the lush growth of new, young trees emerges from the burned ground. Today, decades after the 1988 fires, those young trees are renewed forests, once again filling in vistas. Some visitors still feel the Yellowstone they knew and loved is gone forever. But Yellowstone is not a museum—it is a functioning ecosystem in which fire plays a vital role. Vegetation and Watersheds The vegetation in the Greater Yellowstone Ecosystem has adapted to fire and, in some cases, is dependent on it. Some plant communities depend on the removal of the forest canopy to become established. They are the first to inhabit sites after a fire. Other plants growing on the forest floor are adapted to survive at a subsistence level for long periods of time until fires open the canopy. Fire creates a landscape more diverse in age, which reduces the probability of disease or fire spreading through large areas. One of the two types of cones produced by lodgepole pines, which make up nearly 80% of the park’s forests, is serotinous. Serotinous cones will not In 1988, fires burned a mosaic covering 1.4 million acres in the Greater Yellowstone Ecosystem as a result of extremely warm, dry, and windy weather combined with an extensive, highly flammable forest cover. Trees in Greater Yellowstone are adapted to fire. This serotinous cone from a lodgepole pine tree was opened by fire, allowing it to release its seeds. Some soils respond quickly after fires, but others may continue to support little vegetation. where conditions that enable fires to burn are infrequent. In 1988, 28% of the park’s whitebark pine burned, though it grows in open, cold, high-altitude habitats that accumulate fuel very slowly and have only a short season between snowmelt and snowfall during which fires can ignite and carry. Caches of whitebark pine seeds collected by red squirrels and Clark’s nutcrackers and the hardiness of whitebark pine seedlings on exposed sites give this tree an initial advantage in large burned areas over conifers dependent on wind to disperse seeds. However, this slowgrowing and long-lived tree is typically more than 60 years old before reaching full cone production, and young trees may die before reproducing if the interval between fires is too short or if faster-growing conifers overtake them. Tree seedlings sprout and grow at variable rates between the surviving trees and the fallen and standing snags. As root systems of standing dead trees decay and lose their grip on the soil, the trees fall— sometimes hundreds at once in the presence of a strong wind. However, many trees remain upright for more than a decade after dying by fire or other cause. Fires may stimulate regeneration of sagebrush, aspen, and willows, but their growth is also affected by other influences such as climate and wildlife browsing. Aspen have thin bark, but the clones are connected by a network of underground roots that can survive even very hot surface and crown fires. Although the above-ground stems may be killed, fire stimulates the sprouting of suckers from the roots, and fire leaves bare mineral soil suitable for the establishment of aspen seedlings. Soils in Yellowstone that support little vegetation have been largely unaffected by fire. Soils that have dense, diverse vegetation before a fire are likely to Fire 165 FI RE release their seeds until the resin sealing them melts, requiring a temperature of at least 113°F (45°C). This adaptation helps ensure the seeds do not disperse until fire creates conditions that favor the establishment of lodgepole pine seedlings: diminished litter on the forest floor and plenty of sunlight through an open canopy. Fire can limit trees in the grasslands of Yellowstone, such as the Lamar and Hayden valleys. For example, Douglas-fir seeds require conditions that exist only in rare microhabitats in these grasslands. If a seed reaches such a microhabitat during a favorable year, a seedling may develop. Once the tree is growing, it begins to influence the immediate environment. More tree habitat is created and a small forest island eventually appears. Periodic fire kills the small trees before they have a chance to become islands, thus maintaining the grassland. Mature Douglas-fir trees have thick bark that resists damage by surface fires. In the past in areas like the park’s northern range, frequent surface fire kept most young trees from becoming part of the overstory. The widely scattered, large, fire-scarred trees in some of the dense Douglas-fir stands in the northern range are probably remnants of these communities. Although Engelmann spruce and subalpine fir are thin-barked, they grow in cool, moist habitats FI RE respond quickly after the fire with a variety of species and nearly complete cover. Though above-ground parts of grasses and forbs are consumed by flames, the below-ground root systems typically remain unharmed, and for a few years after fire these plants commonly increase in productivity because fire rapidly releases nutrients from wood and forest litter. The regrowth of plant communities begins as soon as moisture is available, which may be within days at some sites. Plant growth was unusually lush in the first years after the 1988 fires because of the mineral nutrients in the ash and increased sunlight on the forest floor. Moss an inch or more thick became established in burned soils, and may have been a factor in moisture retention, promoting revegetation and slowing erosion. The amount of soil loss and sediment deposits in streams after the 1988 fires varied greatly. Although extensive erosion and mud slides occurred along the Gibbon River after heavy rains in the summer of 1989, it is not known how much the fires contributed to this. Vegetation regrowth slowed this erosion by 1991. About a quarter of the Yellowstone Lake and Lewis Lake watersheds and half of the Heart Lake watershed burned to some extent, but no significant changes have been detected in stream bank erosion, substrate composition, channel morphology, nutrient enrichment, or plankton production, nor have any discernible fire-related effects been observed in the fish populations in the six rivers that have been monitored regularly since 1988. Wildlife Wildfires do not significantly affect the abundance of most wildlife species in Yellowstone. Relatively few animals died as a direct result of the large fires in 1988, and most of those deaths were caused by smoke inhalation. Of Yellowstone’s seven native ungulate species, only the moose has experienced a population decline that appears to have persisted since 1988. Although moose population estimates have been imprecise, it appears that with less willow and subalpine fir available for winter browse, and snow accumulating more deeply with many forest canopies gone, moose winter mortality increased. Mortality in all ungulate species was unusually high in the winter after the fires, but it is difficult to know how much of that was the result of burned forage rather than drought, large herd sizes, and the 166 Yellowstone Resources and Issues Handbook, 2019 relatively severe winter. Elk, bison, and deer populations soon rebounded. Of the 38 grizzly bears wearing radio transmitters when the fires began, 21 had home ranges burned by one or more of the fires. Thirteen of those bears moved into burned areas after the fire front had passed, three adult females without young stayed within active burns as the fire progressed, three bears remained outside the fire perimeters, one adult female was not located for another two years, and another adult female was never located again at all. In a study from 1989–92, bears were found grazing more frequently at burned than unburned sites, especially on clover and fireweed. Even though bear feeding activity in some whitebark pine areas decreased substantially, the fires had no discernible impact on the number of grizzly bears in the Greater Yellowstone Ecosystem. Rodents probably had the highest fire-related mortality of any mammals. Although many could escape the fires in burrows, others died of suffocation as the fires came through. They also were more exposed to predators because they temporarily lost the cover of grasses and other plants. But, because of their capacity to have multiple litters with many young per year, rodents quickly repopulated burned areas. Most birds were not directly harmed by the fires, and some benefited. Raptors hunted rodents fleeing the fires, but young osprey that were still in their nests died. Post-fire habitat changes helped some birds. Cavity-nesting birds, such as Barrow’s goldeneye, flickers, and bluebirds had many dead trees for their nests. Robins and flickers found ants and worms more easily. Boreal owls, however, lost some of the mature forests they need. Wildlife continue to use burned areas after fires. Managing a Natural Process Working Across Boundaries Wildfire is a great example of interagency cooperation and coordination. Federal agencies, state and local governments, and private contractors all play a role in managing fire in the park. For example, the National Park Service sometimes relies on Forest Service smoke jumpers to assist with the park’s remote fires. In return, the National Park Service sends its helicopter or engine to the Silver Gate or Cooke City areas, which are located on or adjacent to the Custer Gallatin and Shoshone national forests. Since 2009, the park’s wildland engine has been staffed by both National Park Service and Forest Service firefighters. Programmable radios ensure communication between National Park Service and Forest Service dispatch, which improves firefighter safety. The National Park Service is also working with its partners to develop Community Wildfire Protection Plans to help plan and prepare for a wildfire that may threaten homes. FI RE The National Park Service allows lightning-ignited fires to burn in Yellowstone provided they are not a threat to human life and property. The park is required to protect human life as well as the approximately 2% of Yellowstone’s 2.2 million acres that are considered developed (e.g., roads, buildings, and other infrastructure) from the threat of fire while at the same time letting wildfire carry out its ecological role in the landscape as much as possible. Yellowstone National Park operates under the 2009 Federal Wildland Fire Policy, which continues to evolve with experience and new knowledge. For example, current guidelines allow firefighters to manage a natural fire for multiple objectives. In the past, fires were required to be categorized as “suppression” or “fire-use for resource benefit.” Now, firefighters can suppress one flank of a fire to protect structures and people while allowing another flank to burn to achieve natural fire benefits. The Antelope Fire of 2010 was an example of managing a fire for multiple objectives. It was suppressed on its west flank to protect people using the roads, and other values at risk. It was monitored, but not suppressed, as it moved south and east away from developed areas. A similar strategy was used in the 2009 Arnica Fire, which burned in 300-year-old lodgepole pine forests but threatened visitor travel, power lines, and Lake Village. Monitoring the perimeter and growth of the Maple Fire, 2016 History of Fire Management Fire suppression in Yellowstone National Park began with the arrival of the US Army, which was placed in charge of protecting the park in 1886. The Army, which was in Yellowstone until 1918, successfully extinguished some fires in the belief that suppression would help save the forests. However, it is difficult to determine how much effect a small group of men could have had on overall fire frequency or the extent of fires in a large park without motorized vehicles or good roads. Fire suppression was most successful on the grasslands of the northern range, which were relatively accessible from the park headquarters in Mammoth Hot Springs. More effective fire fighting techniques and airplanes became available after World War II, but even then, fire suppression did not result in a significant increase in fuel loads except perhaps on the northern range. Records indicate fire was almost completely excluded (suppressed) from the Douglas-fir, sagebrush steppe, and aspen communities on the northern range from 1886 until 1987. By the 1940s, ecologists recognized fire was a natural and unavoidable change agent in many ecosystems, including relatively arid portions of the Rocky Mountains. In the 1950s and 1960s, other parks and forests began to experiment with controlled burns. In 1972, Yellowstone became one of several national parks to initiate programs that allowed some natural fires to burn. Two backcountry areas in the park totaling 340,000 acres, Mirror Plateau and Two Ocean Plateau, were designated as locations where natural fires could burn. Fire 167 FI RE After three years, during which 10 fires burned a total of 831 acres in the two natural fire zones, the non-suppression area was expanded to include most of the park, except for developed areas and a buffer zone at the park boundary. Starting with Yellowstone National Park and Bridger-Teton National Forest in 1976, cooperative agreements were adopted among all Greater Yellowstone federal lands that by 1986 allowed natural fires to burn across shared public-land boundaries. From 1972 to 1987, 235 fires were allowed to burn 33,759 acres in Yellowstone. The summers of 1982–1987 were wetter than average, which may have contributed to the relatively low fire activity during that period. Yellowstone’s fire managers began revising the park’s fire management plan. The new plan permitted some lightning-caused fires to burn under natural conditions; provided for suppressing fires that threatened human life, property, special natural features, and historic and cultural sites; and recommended prescribed burns when and where necessary and practical to reduce hazard fuels. It was in the final stages of approval in spring 1988. However, Yellowstone’s “new” fire management plan was suspended in July 1988 as a consequence of the large fires that occurred that summer. After these fires, a national policy review team examined the national fire policy again and reaffirmed the importance of natural fire policies in national parks and This old fire truck was pressed into use during the 1988 fires. Fire management policy, like the equipment, has been updated many times since that fiery year. wilderness areas. However, the report also offered recommendations: establish more specific criteria for conditions under which fires are permitted to burn, and increase efforts to reduce hazard fuels near developed areas. These recommendations were incorporated into Yellowstone’s 1992 fire management plan. Other revisions occurred to the park’s fire management plan in 2004 and 2014. The 1988 Fires The Yellowstone fires of 1988 have been described as being instrumental in the public’s understanding of the role of fire in ecosystems, history-making, and career-building. In June of 1988, park managers and fire behavior specialists allowed 18 lightning-caused History of Fire Management in Yellowstone The Issue For the first 100 years of the park’s existence, managers believed fires had to be extinguished to preserve park resources. Subsequent scientific research revealed • • fires have occurred in Yellowstone for as long as there has been vegetation to burn, • 1972: Yellowstone begins allowing some natural fires. • • fire plays a role in creating the vegetation patterns of the landscape, 1972–1987: 235 natural, unsuppressed fires burned 33,759 acres—mostly in two dry years: 1979 and 1981. • fire is a part of the ecosystem park managers want to preserve, and • suppressing fires alters the natural landscape and diminishes diversity. History • 1886–1918: US Army suppresses fire in Yellowstone. 168 1940s: More effective fire fighting techniques become available after World War II. Around the same time, ecologists recognize fire is a natural and unavoidable change agent in many ecosystems. • Spring 1988: Approval of a new fire management policy for Yellowstone is suspended. • 1988: 793,880 acres burn in Yellowstone, sparking an increase in the public understanding and acceptance of the role of fire in wildland areas. Yellowstone Resources and Issues Handbook, 2019 • 1989: A national policy review team reaffirms the importance of natural fire policies in national parks and wilderness areas. • 1992: Yellowstone issues a new fire management plan incorporating the 1989 review team’s recommendations. • 2004: Yellowstone’s fire management plan is revised. • 2009: Yellowstone begins operating under the 2009 Federal Wildland Fire Policy, which allows firefighters to manage fires for multiple objectives. • 2014: Yellowstone’s fire management plan is revised. Significant Events during the 1988 Fires Date Event June 14 Storm Creek Fire begins. June 23 Shoshone Fire begins. June 25 Fan Fire begins. June 30 Red Fire begins. July 5 Lava Fire begins. July 11 Mink and Clover fires begin. July 14 On a backcountry fishing trip near the eastern border of Yellowstone National Park, Vice President George H.W. Bush must leave early when fire comes close to camp. July 21 Yellowstone National Park begins suppressing all fires. July 22 North Fork Fire begins. July 25 Fire camp crew jumps into West Thumb Bay to escape flames. August 20 “Black Saturday”: Fires double to more than 480,000 acres. September 3 Storm Creek Fire burns over Silver Tip Ranch, north of Yellowstone National Park; the historic ranch survives. September 7 Fire storm blasts Old Faithful area; Old Faithful Inn is saved, and no one is injured. September 10 Residents of Mammoth Hot Springs evacuate as fire moves across Bunsen Peak toward the area. September 11 Rain and snow fall. More than $120 million was spent fighting the fires in the Greater Yellowstone Ecosystem. Rain and snow in September finally stopped the advance of the fires. FI RE fires to burn after evaluating them, according to the fire management plan. Eleven of these fires burned themselves out, behaving like many fires had in previous years. The spring of 1988 was wet until the month of June,

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