The discovery of invasive zebra mussels in a reservoir near San Francisco has Oregon officials worried that they might show up in their state.
It's the first time zebra mussels have been found west of the Rockies.
Boating was prohibited on reservoir three miles southwest of Hollister after the zebras mussels were discovered.
The zebra and their cousins the quagga arrived in the Great Lakes in the 1980s in ballast water dumped from ships from eastern Europe.
A single female of either species can produce up to a million eggs per year.
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