Seven hundred forty-seven forest fires burned 2502 ha in Olympic National Park, Washington (exclusive of the coastal strip), from 1916 to 1975. The 274 lightning fires accounted for 81 percent of the area burned; 37 fires larger rhan 4 ha accounted for 96 percent of the area burned by lightning fires. Lightning started fires in only 22 of the 60 years, although 3-50 thunderstorms per year occurred during the summers of a 19-year sample period. Probability of one or more fires resulting from a thunderstorm depended on the number of days without 2.5 mm of rain preceding the storm. Eighty-seven percent of the fires and all but one of the fires larger than 40 ha burned in the northeasterly half of the Park, presumably because of lower precipitation. More than half of the fires started above 1220 m elevation, and four-fifths above 915 m. Differences in fuel types and quantities had little influence on fire occurrence or behavior. Most fires started and most areas burned in the subalpine zone, which has the lightest, least continuous fuels. © by the Northwest Scientific Association. Abstract reproduced by permission.