PORTLAND, Ore. -- In this famously liberal city, under skies that obligingly turned from habitual gray to clear blue, Democratic presidential front-runner Barack Obama on Sunday drew the largest crowd of his 15-month marathon campaign for the presidency.

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Sixty-thousand people packed into a park alongside the banks of the Willamette River to listen to Obama, with another 15,000 left standing outside the gates, according to city fire officials. Hundreds more anchored their motorboats, or floated in kayaks and canoes.

That's far more than the 35,000 people who showed up to hear Obama in Philadelphia last month, at his previous biggest rally.

Even after months on the trail, Obama seemed slightly stunned by the size of the crowd, saying, "Wow, wow, wow" as he surveyed the audience.

"We have had a lot of rallies," he said. "This is the most spectacular setting, the most spectacular crowd we have had this entire campaign."

Portland is a Democratic stronghold, known for its bike paths and green ethos. It was one of the few cities in the country to briefly allow gay marriage, frowns on plastic bags and chain restaurants alike and was christened "Little Beirut" by no less than President George H.W. Bush.

In August of 2004, then-Democratic presidential nominee John Kerry held a large rally in the same location, drawing about 45,000 people.

But on Sunday, Obama topped that without even being the official nominee, speaking to a crowd filled with sunscreen-smeared babies in sun hats, union members in matching T-shirts, elderly ladies fanning themselves under the hot sun and 20-somethings dancing to his opening act, the Portland-based band The Decemberists.

Some voters lined up before dawn to see him, including Michelle Kay.

"We are all so sick of Bush, his lies, the war," she said. "When Obama came out he was so honest, so refreshing."

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Others arrived at the last minute, such as Afang Tang-Christianson, of Beaverton, and her husband, Daniel. She is due to give birth to twins in the next week or two, and the two had spent the morning at the hospital when she began feeling early contractions.

But after leaving, she said they came straight to the rally, adding, "It's all about a new beginning, a new start. We are really hoping for change in Washington."

In his speech, Obama was careful to nod to his opponent, Sen. Hillary Rodham Clinton, calling her "smart and tough," which drew approving applause from the crowd.

But he quickly moved to sharp criticism of the presumptive Republican nominee, Arizona Sen. John McCain, repeatedly linking him with President Bush, who is lambasted on bumper stickers all over Portland. He drew loud cheers for his condemnation of the Iraq war and for his nod to Portland's mass transit and bicycle culture.

"If you vote for me, I promise we will not just win Oregon, we will win this nomination, we will win this general election and we will change the world," he said.

Demographically, Portland and its suburbs are stocked with the kinds of people who have been supporting Obama in droves: young, progressive, well-educated and financially stable.

Portland is also overwhelmingly white, though Hispanic and Asian groups have a presence in the city. That deprives Obama of one of his most dependable voting groups, African-Americans. Pollsters, however, have said Obama should win Oregon's Tuesday primary.

But he won't be in the state to celebrate. The Obama campaign announced it will spend Tuesday night in Iowa, a significant battleground state in November, as the candidate and his staff try to signal an end to the long primary season.