For thousands of years, wildfires have occurred on the landscape that is now called Olympic National Park. Evidence of past burns comes from both historic records and environmental clues dating back to the last ice age. Visitors hiking in the Morse Creek and Elwha River valleys can see the effects of past fires in the forest growth patterns. Patches of forest that burned decades or centuries ago can be distinguished by their relatively young stands of Douglas‑fir amid the surrounding mixed conifer old‑growth forest.
Fairly complete documentation exists in park archives for fires from about 1916 to the present. Prior to that, written records are anecdotal. Prehistoric fire data must be gathered indirectly from analysis of charcoal deposits, fire scarred trees, and ages of regenerating forest stands determined from tree rings. Fire history research is important in order to fully understand the frequency, intensity and effects of the region’s fire regime.
Evidence from tree rings indicates that much of the north, east and south sides of the Olympic Peninsula burned during episodes of drought about 300‑500 years ago. Analysis of fire scarred trees indicates that another cycle of prehistoric fires burned many east side watersheds about 250 years ago. The relatively dry east side of the peninsula shows evidence of more frequent and larger fires than the wet west side.
Currently, the extent to which Native Americans used fire on the Olympic Peninsula is largely unknown. Government Lands Office maps of the late 1800's show locations of many burned areas along the coastal strip, and it has been hypothesized that coastal Native Americans burned to clear land, improve game habitat, expose root crops and maintain cranberry and bracken fern in selected sites. It is possible that the small "prairies" near the coast were created or improved by such burning, but no conclusive evidence has been found to date.
The Historic Record
The influx of new settlers around the turn of the century brought with it a spate of large fires started by land clearing, road building and logging efforts on the peninsula. Two memorable large fires from that period were the Dungeness Fire of 1890-1891, which burned about 30,000 acres, and the Sol Duc Burn of 1907, which swept through 12,800 acres of Kloshe Nanitch Ridge in a single afternoon.
While few records exist about the area now known as Olympic National Park during this early period, and most available records relate to fires outside of the present park boundary, historians do have information from other sources. During an early survey of the Olympic Forest Reserve (1898-1900), explorer Theodore Rixon noted evidence of fires throughout the reserve, particularly in the Elwha River Drainage, near Mt. Angeles, in the Sol Duc Valley and along High Divide.
A more recent major burn came in 1978 with the Hoh Fire. Started by lightning on a steep south-facing slope, it smoldered and crept on the ground until hot east winds started. The east winds dried out the fuels, causing the fire to burn hotter and ignite the tree crowns. The flames did not stop spreading until these winds died two days later. Although fire crews were immediately dispatched to the fire when it was discovered on August 7, the fire was not contained until August 14, and not declared out until mid-December. It was 1050 acres.
Lightning-caused fires have accounted for approximately half of the ignitions and two thirds of the burned acreage at Olympic National park since it was established in 1938. Natural fire occurrence is directly related, but not proportional, to lightning incidence levels. It is rare for a summer to pass without at least one period of lightning activity. Lightning incidence is greatest during July and August, though storms capable of igniting fires have occurred from early spring to mid October. Lightning storms generally track across the park in a southwest to northeast direction. The greatest numbers of ground strikes have been recorded in the upper Quinault, Elwha and Skokomish River drainages. The majority of subsequent fires have developed in the Elwha River drainage and Hurricane Ridge area. However, isolated lightning storms have occurred over all areas of the park, including the coastal strip.
Lightning storms are typically followed by light to moderate amounts of precipitation. The rainfall may extinguish the fires, while high fuel moisture inhibits spread. However, prolonged periods of warm, dry weather, especially in combination with east winds, often reveal numerous latent "sleepers." The Hoh Fire (1978) was discovered 13 days following known ignition and the Chimney Fire (1981) 23 days after probable ignition.
While most lightning fires are less than a quarter acre in size, occasional large fires during dry periods account for most of the burned acreage. Large lightning fires include the 1978 Hoh Fire, the 1981Chimney Fire, and the recent 2009 Heatwave Complex fires.
In the past four decades more fires were started by humans than by lightning, but human-caused fires account for less acreage. Human-caused fires have been concentrated near developed recreation sites or along backcountry trails. Early detection and improved suppression methods have kept most of these fires to less than a quarter acre in size.
The largest single fire since the establishment of the park was not started by lighting. The 1985 Beaver Fire, which burned 1,170 acres, was ignited by an illegal campfire. The second largest human-caused fire in park history was the 245-acre Deer Park Fire in 1988, which was also caused by a campfire. In both cases, the campfires were illegally built during periods of high fire danger when fires were banned.