The Thirtymile Fire was first reported on July 9, 2001 in the Okanogan National Forest, approximately 30 miles (48 km) north of Winthrop, Washington, United States.

The wildfire had been caused by an unattended campfire that spread rapidly in the hot and dry weather in the Pacific Northwest.

The fire burned 9,324 acres (38 km2) of forest land dominated by Douglas-fir and lodgepole pine trees in the Chewuch River canyon.

Daniels pleaded guilty to two misdemeanor charges of making false statements to investigators as part of a plea deal; he was sentenced to three months of work release.

[5] High temperatures, low humidity, and extended drought conditions combined to create the potential for extreme fire behavior.

At around midnight, the incident commander requested additional firefighters and resources, stating that the fire must "be taken care of tonight because if it hits that slope it is going to the ridge top.

[15] The Northwest Regulars #6 (NWR #6) were a Type 2 fire crew consisting of 21 members from two Ranger Districts in central Washington.

[23] With the only escape route blocked, Ellreese Daniels drove the 13 members of Squads 1 and 2 up the canyon looking for a safe place to wait out the fire.

The location had relatively sparse vegetation and was flanked by a large rock scree to the west and the Chewuch River to the east.

Daniels instructed everyone to deploy their fire shelters—last-resort safety devices designed to protect wildland firefighters from heat and deadly gases.

Minutes after deployment, two of the firefighters on the rock scree abandoned their fire shelters: Thom Taylor ran and jumped in the river, while Jason Emhoff sought safety in the crew's van.

Jason Emhoff experienced third degree burns to his hands as a result of attempting to put out flames in his shelter without wearing gloves.

All four—Tom Craven, of Ellensburg, and Devin Weaver, Jessica Johnson, and Karen FitzPatrick, all of Yakima—had died as a result of asphyxia due to inhalation of superheated products of combustion.

The investigation team first met in Twisp, Washington on July 11 and began conducting interviews, examining the fatality scene and analyzing the fire.

[33] On September 26, the team released their findings in a report which found that "leadership, management, and command and control were all ineffective due to a variety of factors".

[34] According to the report, numerous safety rules were broken, the fire's potential growth was disregarded, and leadership failed to communicate effectively and enforce orders.

[35] Additionally, the investigation found two major failures in leadership which led to the fatalities: the decision to re-engage the fire and the lack of preparation for a burnover at the entrapment site.

[39] The report also found that after the entrapment, incident commander Ellreese Daniels took no actions to improve the deployment site or prepare the crew.

[40] Following the release of the report, the Forest Service sought disciplinary action against 11 employees, ranging from termination to letters of reprimand.

[43] Prosecutors alleged that Daniels was grossly negligent while supervising the fire, and that he lied to Forest Service and Occupational Safety and Health Administration investigators about ordering firefighters to come down off the rock scree.

The Roslyn memorial is open to the public and includes a rock and charred trees from the spot where the firefighters died, as well as various statues, plaques and pictures.