Pete Tunstall leans on his rake while at his home that burned along the south side of Ramsey Road near State Route 92 in the Monument Fire. Tunstall lived in this house since 1969. More than 60 houses have been destroyed or damaged since the fire started on June 12. Arizona Daily Star/ Dean Knuth

As I wrote about last week, the Monument Fire is the third major Southern Arizona fire this summer that started in rugged, mountainous corridors frequently used by people and drug smugglers. That's led to speculation that some, or all, of these fires may have been caused by illegal immigrants or smugglers.

That speculation was brought to the national stage last weekend by Sen. John McCain, R-Ariz., when he said that there was "substantial evidence" that border crossers were partly responsible for wildfires in the state. Despite being blasted by critics including Rep. Raúl Grijalva, D-Ariz., that he was "provoking an extreme anti-immigrant and anti-Latino atmosphere in Arizona," McCain stood behind his comments.

On Tuesday at a press conference, Cochise County Sheriff Larry Dever backed McCain's assertion when asked about the origin of the Monument Fire burning south of Sierra Vista at a Tuesday morning press conference. While acknowledging that anything is a possibility outside of lightning, Dever said he believes it was most likely started by smugglers or illegal immigrants, according to this Reuters story and this KVOA story.

"It wasn't the rabbits or the rattle snakes that started this fire, it was human beings, and the only human beings believed to be occupying (the area) were smugglers or illegal aliens," Dever said.

Drawing on his 35 years of law enforcement in Cochise County, Dever said it's a "90 to 100 percent" probability it was started by smugglers or illegal immigrants, according to the video on the KVOA website.

He pointed out — like many residents in the area have — that the Coronado National Forest had been closed to the public since June 9 at noon. The Monument Fire started on June 12 at about noon, right near the U.S.-Mexico border.

"So, whoever started the fire was there illegally," Dever said.

Border Patrol agents have access as needed to the Coronado National Forest, preventing illegal immigrants and smugglers from having unfettered access to the corridor, said Brandon Judd, president of Local 2544, the union for Arizona Border Patrol agents.

Forest Service officials have said the Monument Fire was human caused but have repeatedly declined to speculate on who and what set the blaze, citing the ongoing investigation.