It's a family tradition for many, piling into the truck and heading out to cut firewood for the winter, but there may be danger lurking in those logs you're hauling home.

Leigh Greenwood with the Nature Conservancy is director of the 'Don't Move Firewood' campaign.

"The message is that it's good to use firewood, but you should be using it fairly near where it's coming from," Greenwood said. "For instance, if they go out to the forest with a national forest firewood permit , that's fine, as long as you live fairly near that forest. However, if you gather that firewood in Montana, and truck it, say, to Minnesota, that's against the law."

Greenwood said the problem, is insects and other invasive species.

"For the protection of trees, we don't want to move invasive species to other trees," she said. "Invasive species can move on their own a little bit, but they can move very far when people move them. It's a really similar situation as to what may have happened on the Yellowstone River this summer, where boats could have moved that disease between different bodies of water. In the same way, contaminated firewood could move damaging insects to new forests."

Greenwood details some of the pests that could be hitching a ride in your firewood.

"One of the insects that you could accidentally move is the pine beetle," she said. "In other parts of the country there are other insects, like the emerald ash borer, but that insect is not yet in Montana. We've done research on firewood sold at convenience and hardware stores, and have been impressed with how local that firewood supply is."

Greenwood suggests that anyone with questions contact their regional forester, or the county extension agent.