The Highway Patrol said the truck rolled over several times and Appleyard, who was not wearing a seat belt, was ejected from the truck and died as a result of the collision at 5:10 p.m. on Thursday.
James said Appleyard had been missing for a couple of days, and federal officials involved in the Mendocino Complex Fire work had put out a "be on the lookout" alert to help find him.
Appleyard's body was found on Saturday, almost exactly 48 hours after the crash, according to the CHP.
Appleyard was "assigned to fire suppression repair work" in the national forest, federal officials said in a news release Monday.
"The driver of the vehicle was part of the log removal process," Punky Moore, a spokeswoman for the Mendocino National Forest, said in an email.
Appleyard worked for Oroville-based J.W. Bamford Logging, according to the coroner's office. Representatives of the company did not respond to requests for comment.
When asked about the days-long search for Appleyard and the work his company was contracted to do for the forest service, Moore said she did not have any further information.
Bamford Logging is licensed and authorized to conduct forest tree cutting and removal operations, according to a Cal Fire listing.
Workplace regulators are not investigating the death.
Frank Polizzi, a spokesman for California's Department of Occupational Safety and Health (Cal/OSHA), said because the crash took place in a national forest, it's outside of the state's jurisdiction.
Leo Kay, a spokesman for the U.S. Department of Labor, said the crash was not work related, noting that Applegate crashed his personal vehicle after hours, so federal OSHA investigators did not plan to look into the case.
Applegate's death is the second fatality involving someone working the Mendocino Complex Fire.
Matthew Burchett, a 42-year-old battalion chief from Utah, was killed on Aug. 13.
The crash also marks the fourth death of a contractor working a wildfire in California in the last two years and just the second in the last several months.
Donald Ray Smith, an 81-year-old bulldozer operator from El Dorado County, was killed in the massive Carr Fire on July 26.
Garrett Paiz, a 38-year-old water tender driver from Missouri, was killed during last October's North Bay fires when the water tender he was driving crashed in Napa County.
And Robert Reagan, a 35-year-old bulldozer operator from Fresno County, was killed during the Soberanes Fire in Big Sur in July 2016.