The Cantara Loop Spill: The Day the Sacramento River Died

On July fourteenth, nineteen ninety-one, a Southern Pacific tank car derailed at the Cantara Loop, where the railroad tracks curve tightly along the Sacramento River north of Dunsmuir, and released nineteen thousand gallons of metam sodium into the water.

Metam sodium is an agricultural fumigant. When it mixes with water, it produces methyl isothiocyanate, a toxic gas that dissolves back into solution and moves with the current. The plume moved downstream at river speed. Over the following days it killed virtually every living thing in the upper Sacramento River for about forty-one miles: an estimated one million fish, tens of thousands of crayfish, most of the macroinvertebrate base that the rest of the food chain depended on. The river was closed to fishing for two years.

Southern Pacific paid approximately thirty-eight million dollars in settlement. At the time, it was one of the largest inland chemical spill settlements in United States history.

The river has substantially recovered. Fish populations rebounded significantly within five years. Steelhead trout thrive in the river today. Some invertebrate communities took more than a decade to return to pre-spill levels, and researchers who studied the recovery noted that the post-spill baseline was not identical to what had been there before. Recovery is not the same as replacement. But the river is alive again.

The railroad still runs this canyon. The curves are the same curves.