The Tillamook Burn was a series of forest fires in the Northern Oregon Coast Range of Oregon in the United States that destroyed a total area of 350,000 acres (1,400 km2) of old growth timber in what is now known as the Tillamook State Forest. There were four wildfires in this series, they spanned the years of 1933–1951. By association, the name Tillamook Burn also refers to the location of these fires. This event is an important part of the local history of Oregon.
The first was started in the Gales Creek Canyon on August 14, 1933, when a steel cable dragging a fallen Douglas fir rubbed against the dry bark of a wind-fallen snag. The snag burst into flame, and the wildfire that grew out of this burned 350,000 acres (1,400 km2) before it was extinguished by seasonal rains on September 5. An oppressive, acrid smoke filled the neighboring valleys; ashes, and cinders, and the charred needles of trees fell in the streets of Tillamook; and debris from the fire reached ships 500 miles (800 km) at sea. The loss in processed lumber was estimated to have been $442.4 million in contemporary (1933) dollars—a serious loss not only to the timber industry at the time, but also to a nation struggling with the Great Depression. Salvage operations were immediately begun to harvest usable portions of the burned wilderness. A Civilian Conservation Corps member was the only known human casualty of fighting the fire.
The speed with which a forest fire can spread in heavy fuels under the most hazardous conditions is well illustrated by this fire. From August 14 at 1 p.m. until the early morning of August 24 the fire had burned about 63 square miles (160 km2) and it appeared that it might be brought under control soon. Thus, for over 10 days it had burned at an average rate of about 6 square miles (16 km2) a day. On August 24, the humidity dropped rapidly to 26 percent and hot gale force winds from the east sprang up. During the next 20 hours of August 24 and 25 the fire burned over an additional 420 square miles (1,100 km2), or at a rate of 21 square miles (54 km2) per hour along a 15-mile (24 km) front. The fire was stopped only by the fact that the wind ceased and a thick, wet blanket of fog drifted in from the ocean.