Spotlight – Invasive Quagga Mussels Detected in Snake River

In September of 2023, the Idaho State Department of Agriculture (ISDA) confirmed the presence of multiple quagga mussel life stages in the Mid-Snake River. The discovery of quagga mussels in the Snake River marked the first time a rapid response plan had been put into action for quagga mussels in Idaho.

ISDA has closely monitored the Snake River since the initial detections, taking more than 300 samples in the affected area throughout 2024. In September of 2024, ISDA again confirmed the detection of a small number of quagga mussels in the Twin Falls area of the Snake River. As of 2025, sample results show a decreased quagga mussel presence in the affected stretch of river since pre-treatment in 2023.

Treatment and ongoing monitoring plans are underway and updates regarding this effort can be found at Snake River Quagga Overview — Invasive Species of Idaho