RIVERSIDE, Calif. — A California man was sentenced to death on Friday for setting a hillside inferno in 2006 that killed five United States Forest Service firefighters.

The penalty had been recommended by the jury that convicted the man, Raymond Lee Oyler, 38, of murder and arson in March.

In imposing the sentence, Judge W. Charles Morgan of the Superior Court in Riverside County said that Mr. Oyler had “set on a mission — why? no one knows — to create havoc in this county by setting fires of his own design, for his own purpose.”

Judge Morgan added, “He knew young men and young women would put their lives on the line to protect property and people.”

Mr. Oyler remained silent and stared straight ahead as the judge announced the sentence.

Federal and state fire officials said they believed this was the first time the death penalty had been given in a wildfire arson case in which firefighters were killed.

A jury on March 6 convicted Mr. Oyler of 5 counts of first-degree murder, 17 counts of using an incendiary device and 20 counts of arson for setting fires in the mountains of the San Gorgonio Pass, 90 miles east of Los Angeles, over six months in 2006.

The evidence included fire-starting contraptions Mr. Oyler had made of cigarettes and matches, DNA samples on two cigarette butts, and accounts from witnesses, prosecutors said. Mr. Oyler denied setting the blaze that killed the firefighters, although he did admit to starting 11 other fires, Mark McDonald, his lawyer, said in a telephone interview.

Mr. McDonald said Mr. Oyler had told him that he started one fire as a distraction to “break his dog out of the pound,” and set the others out of anger for losing custody of one of his three daughters because of his methamphetamine use.

On Oct. 26, 2006, forest service firefighters joined Riverside County crews already battling a large blaze, known as the Esperanza fire, as Santa Ana winds spread flames over slopes and canyons. While defending an isolated hilltop home, the five victims were caught in a “burn over,” according to testimony by fire investigators. A wall of flames 70 feet high, fed by 40 mile-an-hour winds and temperatures of up to 1,300 degrees, rolled over them.

Three firefighters — Jess McLean, 27; Jason McKay, 27; and Daniel Hoover-Najera, 20 — died on the slope. Two others — Captain Mark Loutzenhiser, 43; and Pablo Cerda, 23 — died later at a hospital with scorched lungs and third-degree burns over most of their bodies.

It was the most firefighters to die in a wildfire since 14 died in Colorado in 1994, said Ken Palmrose, a spokesman for the National Interagency Fire Center in Boise, Idaho,

During the trial, prosecutors showed large photographs of the men’s charred bodies, said Gloria Ayala, Mr. Hoover-Najera’s mother.

“I had been told he died of smoke inhalation,” Ms. Ayala said in an interview, “that it took 11 seconds. But when I saw that picture, the only part left with a flesh color was the tip of his nose. I will remember that forever.”