'That's pretty cool' : Obama tours Old Faithful geyser

Swapping political hot water for the real thing, President Barack Obama gasped Saturday as a famed geyser erupted into Wyoming's vast blue skies in Yellowstone National Park.

Obama, with his family along, helicoptered deep into the park for a brief respite from the heated political battle over health care reform -- his number one domestic priority.

His four-day work-hard, play-hard tour mixes trips to some of America's most majestic beauty spots, with the deadly serious business of thwarting Republican attacks on his health care plan.

"Oh, that's pretty good -- Cool," Obama was heard to say to wife Michelle and daughters Malia and Sasha, as the "Old Faithful" geyser spurted thousands of gallons of boiling water and steam into the air.

The geothermal natural wonder erupts every half-an-hour to two hours and has been known to shoot water up to around 180 feet (60 meters), in a natural amphitheatre formed by Yellowstone's towering mountains.

Late on Friday, the president tried a spot of fly fishing for trout, while his family braved frequent heavy downpours to take a thrilling whitewater raft ride in the shadow of Montana's craggy peaks.

On Sunday, the first family was set for another day of adventure tourism with a trip to the Grand Canyon during a visit to Arizona.

But before then, the president had to knuckle down for another political town hall meeting on health care, in Grand Junction, Colorado.