On August 18, 1937, a lightning strike started the Blackwater Fire in Shoshone National Forest, approximately 35 miles (56 km) west of Cody, Wyoming, United States. Fifteen firefighters were killed by the forest fire when a dry weather front caused the winds to suddenly increase and change direction. The fire quickly spread into dense forest, creating spot fires that trapped some of the firefighters in a firestorm. Nine firefighters died during the fire and six more died shortly thereafter from severe burns and respiratory complications. Another 38 firefighters were injured. The fire killed more professional wildland firefighters in the U.S. than any other in the 103 years between the Great Fire of 1910 and the Yarnell Hill Fire in 2013.
The Blackwater Fire consumed 1,700 acres (690 ha) of old-growth forest dominated by Douglas fir trees on the west slopes of Clayton Mountain. At the time the firestorm occurred, the temperatures were about 90 °F (32 °C) and the relative humidity was only 6 percent. Though most of the firefighters consisted of Civilian Conservation Corps (CCC) employees, they were led by more experienced United States Forest Service (USFS) fire managers. Firefighters in the first half of the 20th century used mostly hand tools to suppress wildfires, and all gear was carried by the firefighters or by pack animals. Weather forecasting and radio communication were generally poor or nonexistent.
Investigations and analysis of the event led the USFS to develop better ways to provide a more immediate response to combat fires; one of them was the development of the smokejumper program in 1939. Additionally, the Ten Standard Firefighting Orders, a standardized set of wildland firefighting principles, were developed in 1957. A year after the tragedy, survivors and their fellow employees constructed several memorials at the scene of the incident.
Blackwater Creek originates on the north slope of Sheep Mesa at an altitude of 11,400 feet (3,500 m) in Shoshone National Forest and flows north through Blackwater Canyon. The creek is 12 mi (19 km) long and descends a steep gradient before it empties into the North Fork Shoshone River, across from U.S. Routes 14/16/20 immediately west of Mummy Cave and 15 mi (24 km) east of the border of Yellowstone National Park. The firestorm deaths occurred on the west slopes of Clayton Mountain, approximately 5 mi (8.0 km) south by trail into the canyon. The canyon consists of numerous ravines and small ridges, which form a washboard landscape shaped by extensive erosion of the volcanic igneous rock that constitutes the Absaroka Range. The canyon has moderate to steep slopes with a gradient of 20 to 60 percent. The regional flora is an upper montane mixed-conifer forest dominated by Douglas fir trees. When the fire swept through the area the forest was dense and mature with heavy fuel loads from dead trees, which also had dead limbs extending to the ground, providing a fuel ladder for fire to easily spread into the tree tops.
Early 20th-century firefighting
In 1937, firefighters did not have portable radios for rapid on-scene communication or helicopters to bring supplies and provide water drops. Firefighters had some access to gas-powered portable water pumps (two were set up on the Blackwater Fire), but most used backpack pumps that were manually operated and held limited water. Firelines were dug by handcrews using shovels, axes and pulaskis (a tool that could be used as either an axe or a hoe). Most firefighters wore cotton and wool clothing, which provided poor protection from flames. Additionally, they did not have fire shelters, which first became available in the 1960s but were not mandatory until 1977. Later researchers believe the use of shelters might have saved lives depending on where the firefighters were when the firestorm occurred.
The steepness and ruggedness of the terrain in Blackwater Canyon meant firefighters had to access the fire on foot, carrying all their supplies. On the Blackwater Fire, pack horses were used to ferry supplies from the access roads to an upper base camp. Many of the firefighters were employed by the Civilian Conservation Corps (CCC) and had limited training in wildfire suppression and behavior, as the CCC was mainly engaged in construction projects. After a series of severe and deadly forest fire events in the early 20th century, officials established the 10 am rule in 1935, which recommended aggressive attack on all fires and to have them controlled by 10 am, the day after they are first detected. This was intended to prevent fires from remaining active into the afternoon when the rising temperatures and more turbulent air caused fires to expand and become more erratic. A scientific publication about fire behavior that could be used for widespread training of firefighters first became available in 1951.
Detection and firefighter response
The Blackwater Fire was started by a lightning strike on August 18, 1937, but it remained undetected until early August 20, at which time it was estimated to be about 2 acres (0.8 ha) in size. By the evening, it had expanded to 200 acres (80 ha), and 65 firefighters from the United States Forest Service (USFS), which included CCC company 1852 from the Wapiti Ranger District of Shoshone National Forest and employees of the Bureau of Public Roads (BPR), were constructing fire lines along two flanks of the fire. A gas-powered portable pump was delivered and set up using water from Blackwater Creek by midnight. Another pump arrived after that and firefighters installed 2,000 ft (600 m) of hose line on the north flank of the fire and another 5,000 ft (1,500 m) on the west flank. CCC workers from the National Park Service arrived at 2:30 am on August 21 and started construction of fire line along the north flank of the fire. Meanwhile, increasing winds had begun expanding the fire to the east.
Fire officials believed they needed more manpower, so CCC crews from Bighorn National Forest, 165 mi (266 km) to the east, and other districts of Shoshone National Forest started responding by the morning of August 21. By 12:30 pm, more than 200 firefighters were on duty and involved in digging fire line or in support of the firefighting effort. Along one of the small creeks flowing into Blackwater Creek, a small dam was constructed to pocket water supplies for use in backpack water pumps. Due to a long overnight journey, the CCC members from the Tensleep District of Bighorn National Forest did not commence response to the fire until after noon on August 21. As they arrived, the Tensleep CCC unit were told to relieve the Wapiti CCC unit that had been fighting the fire since the previous evening. More than 50 firefighters commenced construction of a new fire line along Clayton Creek and Clayton Gulch, a ravine extending east from Blackwater Creek. The construction was led by USFS Rangers Alfred Clayton and Urban Post, and their crews consisted mainly of the Tensleep CCC camp and some from other entities.
Radio transmissions from Idaho to a weather service office in Riverton, Wyoming, indicated a dry weather front had pushed through and was heading east. It is believed that forest managers at the Wapiti ranger station received this information, but it did not reach the men on the fire lines because of a lack of radio lines. The USFS did have spotters in an aircraft providing aerial observation of the fire behavior that was radioed to the Wapiti ranger station. At 12:40 pm on August 21, several spot fires were reported near the fire lines by aerial observers. At 1 pm, the weather at Wapiti was 90 °F (32 °C) with an extremely low relative humidity of 6 percent. Winds blowing generally from the southwest increased to 30 miles per hour (48 km/h) as the dry front approached at 3:30 pm. At 3:45 pm, they shifted abruptly from southwest to west, causing increased crowning and spot fires over the fire lines. Convectional winds also increased and the fire front started up the drainage heading east.