Lake Powell and the upper Colorado River are believed to be free of zebra and quagga mussels, but Glen Canyon National Recreation Area officials aren't taking any chances this summer.

Any vessel found with live, adult zebra mussels attached to it will be quarantined until a biologist determines it's safe to launch. Random inspections of all boats entering Lake Powell have already begun, the National Park Service recently announced.

Invasive mussels are still considered a threat to Lake Powell, having already been found in Nevada's Lake Mead. If anyone violates Lake Powell's self-certification and decontamination process to keep mussels out of the ecosystem, they face a mandatory court appearance and a $5,000 fine.