Both Cal Fire and the U.S. Forest Service said they are taking the threats seriously -- but they're not worried, they said.
The agencies tell Action News they're ready for wildfires, no matter what or who causes them.
"Ever since 9/11 we've had a heightened sense of awareness for terrorism and we do talk about that," said Cal Fire Battalion Chief Julie Hutchinson. "In the last three to four years we have had an inkling that it's something that's out there."
al Qaeda's online magazine, 'Inspire,' provides instructions on how to set off the terror events. The magazine describes, in detail, how to follow weather maps to target the driest areas. It also calls for fires in remote, wooded communities.
"Fire season is coming up on us and this is just one more indicator that we need to be ready," said Sierra National Forest Fire Chief Joseph Reyes.
Reyes said his fire fighters prepare for just about everything, including arsonists.
Randy Myers knows about the dangers of wildfires near his home in Yosemite Lakes Park. al Qaeda doesn't scare him, but the fires do.
Last year, three wildfires threatened the area. Officials said the best way to protect against large fires, terrorist caused or otherwise, is to keep a 100 foot clearing around your home.
The Sierra National Forest also passed along this threat information to all of its employees Thursday.