PAGE, Ariz. (AP) -- Officials say the problem of invasive quagga mussels in Lake Powell is bigger than previously thought.
National Park Service and Utah wildlife officials say they've recently detected thousands of adult quagga mussels on canyon walls, the Glen Canyon Dam, boats and other underwater structures.
The discoveries come as falling lake levels expose surfaces that previously were underwater.
Parks officials say they're focused on keeping the invasive species from spreading to other lakes and rivers. They plan to continue educating people on the spread of mussels, and inspecting and decontaminating boats coming in and out of the lake.