Tug boats safely hauled the 174-metre, Seabulk Pride, a double-hulled tanker carrying 16.5 million litres of oil, off a silt bank where it came to rest after being ripped free of its moorings.
"They have pulled it free and it's under its own power now," said a spokeswoman for the US Coast Guard's information centre in Alaska.
"We got it afloat with the tug boats…and it is awaiting Coast Guard inspection to make sure it is sound," the official told AFP. "However, it does not appear that there is any major damage."
The ship became untethered from its moorings when it was struck by fast flowing ice as it was loading fuel at a dock in the port of Nikisi, about 280 kilometres southwest of Alaska's largest city, Anchorage.
The impact sent it drifting out of control about 800 metres into the Cook Inlet, a spot famed for its hunting and fishing, where it ran aground on a silt bank.
"It's lucky as it came to rest in an area that wasn't at all rocky," the Coast Guard official told AFP.
The only spillage was around five barrels (800 litres) of oil that leaked when the loading arm broke as the ship tore free, and three of the barrels were contained on the ship's deck, Coast Guard officials said.
Haunting reminder
The Seabulk Pride, built in 1998, ran aground around 300 kilometres west of Prince William Sound, the scene of one the worst environmental disasters ever after the Exxon Valdez tanker ran aground on March 24, 1989.
The Exxon Valdez was laden with 40,000 tons of crude oil when it hit a reef at night, unleashing an environmental catastrophe.