“Don’t touch any bottles or cans you find,” Craig Thompson told us as we wound our way through oak and manzanita. “And if anything looks fresh, tell me.” Thompson is a research ecologist with the U.S. Forest Service and has been studying fisher populations in California for years, but it’s in the last six that his job has gotten a lot more complicated — and dangerous.
We were walking up a trail toward the site of an illegal marijuana grow, discovered and cleaned up by law enforcement officers about 18 months ago. I’d parked our car less than a quarter of a mile away, in front of a residential house and next to an old fire road that soon petered down to a walking trail and then into almost nothing. We could still easily hear the road traffic, but we couldn’t see it. That proximity to the road yet being virtually invisible is exactly why this site was chosen by illegal growers to raise thousands of pot plants on public land.
The issue of plots of public land hijacked by illegal pot growers is not new. Anyone who has wandered around the Humboldt area of California knows not to stray off trail when hiking. But the extent of California’s pot problem — the areas where it has spread and the depth to which it’s draining the land of water and wildlife alike — is coming to light through years of careful research. The credit for blowing the whistle on the issue goes to one species in particular; in fact, one individual animal in particular. The mysterious death of a fisher, a carnivore in the weasel family, in April 2009 connected the dots between the threatened species’ struggle to reestablish populations in what seems like perfectly suitable habitat, and the ongoing problem of trespass grows on public land.