The FBI has rekindled a decades-long manhunt for a serial arson suspect accused of operating a domestic “eco-terror” cell that lit off more than a half-dozen fires in the 1990s and early 2000s shortly after Los Angeles authorities announced the arrests of a pair of fake firefighters from Oregon – one of whom has a criminal history of arson.

The Los Angeles County Sheriff’s Department told Fox News Digital Sunday that Dustin Nehl, 31, and Jennifer Nehl, 44, were arrested after allegedly impersonating firefighters and driving into a restricted zone in a fake firetruck from a fake department.

The FBI is offering $50,000 for information leading to the arrest of Josephine Sunshine Overaker, a suspected domestic terrorist accused of setting arson fires to spread an animal rights message alongside a group of fellow radicals. She, too, has been accused of posing as a firefighter.

The FBI calls it the “largest eco-related arson in history.” The fire destroyed the luxe Two Elk Lodge restaurant, which was later rebuilt, disabled chair lifts and leveled other buildings, according to authorities. 

Other targets were the Cavel West Meat Packing Plant in Redmond, Oregon, and a barn that belonged to the Bureau of Land Management in Litchfield, California.

Overaker allegedly led an cell of domestic terrorists known as “The Family,” blamed for between $45 million and $80 million worth of damage across 25 arson attacks. To avoid detection, she allegedly shoplifted her bombmaking materials rather than buy them.

Overaker, a Canadian-born American citizen, has a large bird tattoo across her back and may be posing as a firefighter, a midwife, a sheep tender or a masseuse, according to the FBI. She has brown hair, brown eyes, stands 5 feet, 3 inches tall and weighs an estimated 130 pounds. Agents have said she has facial hair on her upper lip.

She has used a number of aliases over the years, including Lisa Quintana, China, Jo and Osha, according to the FBI. She is fluent in Spanish and may have relocated to Spain.

She faces up to life in prison if convicted. 

Fox News’ Stepheny Price contributed to this report.