Hundreds of friends, family, fellow firefighters and community members attended the solemn ceremony at the National Orange Show Events Center in memory of Brent Witham.
The service included an honor guard presentation and a bagpipe procession. A ceremonial bell ringing also took place to mark the "last alarm" for the fallen firefighter.
During the ceremony, Witham was eulogized as someone with a strong work ethic and love of family. He was also remembered as the ultimate prankster.
The 29-year-old's remains were brought home from Montana on Monday.
Firefighters from across Southern California gathered at the San Bernardino air tanker base to salute the fallen firefighter. More firefighters also lined the route to the mortuary.
Witham was battling the Lolo Peak Fire in Montana Aug. 2 when he was struck by a falling tree and killed.
He began his career as a firefighter in 2011 and most recently had been a member of the San Bernardino Vista Grande Hotshots since 2015. He was following in the footsteps of his father and grandfather, who were also firefighters.
Members of the U.S. Forest Service said Witham died doing what he loved.
"There was no doubt he loved being a firefighters. He loved being a hotshot. His second family was the Vista Grande Hotshots, and he loved his crew members as much as any of his family," said U.S. Forest Service Cmdr. Rita Wears.
Witham's younger sister also spoke at the memorial. She described her big brother as someone she was proud to look up to.