Some of the people getting nearly $17 an hour to mop up the largest oil spill in U.S. history are unhappy with how the mess is being handled and 20 quit their jobs.

"We don't even know who our supervisors are," said Chris Christoffersen, who had been staying aboard the USS Juneau.The vessel serves as a floating hotel for the more than 300 cleanup workers laboring - sometimes one rock at a time - to get oil off Smith Island's once-picturesque shoreline.

Christoffersen was one of 20 workers taken back to Valdez during the weekend after quitting. As they lined up to leave, new workers arrived.

Valdez has been the center of the cleanup since March 24, when the Exxon Valdez went aground in Prince William Sound and spilled more than 10 million gallons of crude.

The oil, which has spread across hundreds of square miles, during the weekend reached the beaches of Katmai National Park, a brown bear refuge about 275 miles southwest of Valdez.

Authorities said Monday they are shifting a large cleanup dredge southward from Prince William Sound to follow the drifting oil. They also plan to bring in high-powered warm-water guns to cleanse the rugged shoreline.

"Over the last two days . . . we've discovered a very large amount of oil debris inside of Shelikof Straits," park superintendent Ray Bane said. The 30-mile-wide strait lies between Kodiak Island and the Alaska Peninsula.

"The impact stretches from Shaw Island, on the north side of Cape Douglas, all the way to our southern boundary, and now we've had reports it's been found in Wild Bay, south of us," Bane said.

Monday, was the deadline for Exxon to provide the state with a plan for waste disposal and the cleaning of Gulf of Alaska shorelines.