Nearly four months after the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives began investigating the Palisades fire, investigators set a fire to parts of the Temescal Ridge Trail between Skull Rock and Green Peak on Tuesday night into Wednesday morning.

Investigators with the Bureau of Alcohol, Tobacco, Firearms and Explosives will conduct a controlled burn along the Temescal Ridge Trail between Skull Rock and Green Peak from April 29 through May 1.

ATF investigators said they are testing flame size and location, which is helpful in determining the fire’s origins.