Most illegal marijuana grows are hidden inside someone's basement or greenhouse. But apparently there's also an epidemic of illegal cannabis in America's national forest, and it's becoming a problem.

CBS News recently highlighted a major problem America's national forests are having with illegal marijuana grows. The U.S. Forestry Service says last year federal agents seized 1.4 million marijuana plants growing in national forests, and thousands of pounds of toxic chemicals and trash related to those illegal grows were also found. 

And unlike other operations combating illegal marijuana, the federal government's concern is mostly related to destruction of national forests. In order to maintain these illegal grows, marijuana cultivators are using dangerous pesticides or damaging parts of the environment to keep their stash alive.

In one illegal grow, the cultivators had diverted water from a natural stream to create a reservoir to hydrate their plants. In other sites, they found carbofuran, a banned pesticide in the United States that can kill local wildlife and damage plants growing in the vicinity. 

One U.S. Forestry Service spokesperson says they find around 400 illegal marijuana grow sites each year, and that for every one they find, he estimates there's two or three more that they don't.

So maybe there is one way where the federal government's attacks on marijuana can actually be useful.

(h/t CBS News)