There has been some news about the increasing problem of pot growers using explosives and posting armed guards in sniper locations to protect their crops in remote locations on public lands. Some of the more sophisticated operations use remote cameras to check up on possible thieves or law enforcement efforts.
Be careful out there when you are prospecting, especially near mountain streams as the growers are starting to developing elaborate irrigation systems in areas that have water and soil types suitable for cultivation. These are the same places prospectors are drawn to.
Here's a recent story you must read...
http://www.google.com/hostednews/ap/articl...atiJVgD9E64ET00ASTROBLEME