Posted Wednesday, April 18, 2012 --- 6:45 a.m.

MADISON, Wis. (AP) -- The U.S. Forest Service is again warning hikers and campers to steer clear of pot farms this summer.

Chequamegon-Nicolet National Forest officials say drug trafficking organizations typically plant farms in the spring and harvest their crop in the late summer. They say the tell-tale signs of a farm include isolated tents, garden tools, bags of fertilizer, garbage, disturbed soil and cleared stumps.

Forestry officials say growers may be armed. Anyone who runs into any signs of a farm should leave, try to mark the location by landmarks or waypoints and notify law enforcement.

Police have eradicated about 80,000 marijuana plants in the Chequamegon-Nicolet National Forest over the last two years.

Copyright 2012. The Associated Press.