By Charlie Burr

Oregon is home to some of the most beautiful forests and natural areas anywhere on the planet. It’s time to protect them from illegal marijuana cultivation that trashes our public land, harms wildlife and endangered species and dumps toxins into our rivers and streams.

As Oregonians fill out their ballots, they should join the Oregon League of Conservation Voters and others fighting for a healthier environment by voting yes on Measure 91, a common sense approach to regulating and taxing marijuana production.

From Umatilla to Siskiyou, our forests face a scourge of unregulated marijuana harvesting operations that threaten some of our state’s most special places. In fact, last year saw law enforcement uncover illegal marijuana grow sites in 72 national forests spanning 22 states.

In 2011, officials found 91,000 marijuana plants worth roughly $180 million growing in Wallowa-Whitman National Forest, the largest grow operation in Oregon’s history.

Beyond the eye-popping scale, the operation highlighted the enormous environmental cost of unregulated, illegal marijuana cultivation. Law enforcement uncovered more than 500 pounds of fertilizer, as well as nasty pesticides and herbicides banned in the United States. Growers had doused their plants with “super-toxic” rodenticides that not only kill rodents, but also slowly poison their predators, including the endangered northern spotted owl and Pacific fisher.

Miles of plastic tubing littered the site as growers diverted stream water for irrigation. Nearby streams designated as sanctuaries for endangered steelhead saw sediment, pesticides, fertilizers and solid waste dumped into the water.

In addition to the obvious wildfire danger, illegal growing operations threaten public safety. The growers on the Wallowa-Whitman site were armed with pistols and an Uzi — one of the reasons that Oregon Department of Fish and Wildlife’s number one warning to hunters is the danger of stumbling onto an outlaw grow site. That’s unacceptable.

These lands belong to all of us. It’s time to protect our natural heritage for current and future generations by driving these illegal operations off our public lands and wild places.

Measure 91 would remove incentives to hide marijuana cultivation in national forests and would nearly eliminate these rogue operations. Nobody risks a felony conviction to grow tobacco on federal land, because tobacco is regulated and legal. But as long as marijuana remains illegal, dangerous marijuana operations will pollute our forests and threaten sensitive habitat.

Marijuana prohibition puts our forests at risks, but for what? During the past two decades, youth marijuana use hasn’t decreased. Each year, we spend millions enforcing harsh marijuana laws while diverting law enforcement from more violent crime.

Oregonians with felony marijuana convictions struggle to find employment, housing and a shot at a better life. The nearly 13,000 marijuana arrests and citations in Oregon each year simply aren’t worth the costs to our forests, streams and wildlife.

Oregon doesn’t have to accept the environmental or societal price we pay for this failed policy. We can do more to protect taxpayer land from threats to wildlife, water quality and public safety — starting with reclaiming our forests from the epidemic of illegal grow operations. Let’s regulate and tax marijuana production and put an end to these destructive operations.

There’s a broad and diverse coalition of senior advocates, labor organizations, business leaders and parents calling for sensible reform. The Oregon League of Conservation Voters supports Measure 91 as an important step in the broader fight to protect forests and public lands.

Vote yes on Measure 91 for a healthier environment and strict, smart controls on marijuana cultivation.

— Charlie Burr lives in Portland.