In Northern California’s Shasta Cascade region, a rail line winds through the Upper Sacramento River canyon with a series of twirls and turns that seem inspired by rollercoasters. The highlight is the Cantara Loop, a nearly 360-degree pivot across the river that they used to depict on postcards. It’s gorgeous — surrounded by mountains and lush forest — but it’s also an accident waiting to happen.

On July 14, 1991, a clumsily loaded Southern Pacific train flipped off track at the Cantara Loop, dumping more than 19,000 gallons of toxic soil fumigant into the river. The spill was among the worst inland ecological disasters in California history, extinguishing life so thoroughly along 40 miles of river that even the trees by the shore died. The fallout from the disaster led to safety improvements, including a beefy new guardrail, and after some years the river returned to health. But the derailments never stopped. They are typically harmless, involving some spilled logs or empty railcars, as happened last August. But environmentalists say the close calls portend another disaster ahead. Mike Sabalow, a retired track foreman in Mount Shasta, once told Sacramento News & Review that accidents along the winding canyon are nowhere near as frequent as in the old days, when they could be monthly events. But to eliminate them altogether is wishful thinking. The “shit-happens factor,” he said, never goes away.

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See how scenic — and treacherous — the line is. 👉 YouTube

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