In the recently concluded boat-inspection season, Idaho reports that it inspected more than 47,000 watercraft and intercepted 24 that were carrying invasive quagga or zebra mussels into or through the state. Nearly half came from federal waters in Nevada and Arizona, the state Department of Agriculture reports. State Ag Director Celia Gould said, "The Lower Colorado River system is known to be heavily infested with quagga mussels, and we know that many Pacific Northwest boats spend extended periods of time there. ... Boats that have been in those waters are considered extremely high-risk."

The tiny, fast-multiplying mussels haven't been found in Idaho waters yet, and the state wants to keep it that way. Gould called on federal officials to do more to stop the mussels from leaving already-infested federal waters like Lake Mead and Lake Havasu. "Mussel-fouled boats continue to leave infested waters without proper decontamination," she said. "The federal government needs to do a better job of containing infestations in their waters and preventing the spread of these species to the Pacific Northwest states. We need all hands on deck as we work to protect our waters."

People with watercraft returning from those infested areas can arrange for an inspection by calling the Department of Agriculture at (877) 336-8676; they are also advised to clean, drain and dry their boats, including washing the hull thoroughly with hot water and waiting five days between launches into different waters.