That was in March 2000. Returning to that pool this week, Phelps is the old guy still in the early stages of an Olympic comeback, getting pursued by the new generation.
"I think back then it was different because I was racing with so many older guys and the thing that made me so hungry was wanting to beat every single one of them," Phelps said Wednesday. "Now I'm the old man … I think the biggest thing now is I would like to not let the young bucks beat me. And I think where I am now I'm more focused on what I should be doing at this time of year or what I want to be doing at this time of year."
Phelps is back in the Seattle area as the featured attraction in this weekend's U.S. winter nationals. He will be swimming three events — the 200 meter individual medley on Thursday, the 100 butterfly on Friday and 200 butterfly on Saturday — in the second stage of his preparations for the Rio Olympics next August.
The first part came a month ago at the Arena Pro Swim Series in Minneapolis. Phelps took third in the 100 butterfly, second in the 200 butterfly and won the 200 individual medley, a performance he called "a good place to start."
Those finishes in Minneapolis came after Phelps had done training at altitude, but the benefits of the time swimming at higher elevations wasn't expected to show up there. The hope is the altitude training will show its benefit with Phelps' performance this week.
"Now we have a read on where he is with his first meet, which was close to his last meet last year which is how we like it. And we'll know a lot more after he swims here," Phelps' coach Bob Bowman said.
Barred from the world championships in Russia last summer because of his second drunken-driving arrest, Phelps re-established himself as the world's most dominant swimmer with a turn-back-the-clock performance at the U.S. national championships in August. He posted world-best times in the 100 and 200 butterfly and 200 individual medley that week in San Antonio.
He's embracing the challenge of trying to get back to a fifth Olympics, thanks in part to a stay at a treatment facility, the reparation of his complex relationship with his father and the renewal of his passion for the pool. All of which was detailed in a revealing interview with Sports Illustrated in which Phelps said he was in "a dark place" where he didn't want to be alive after the embarrassing DUI arrest in 2014.
"I'm a lot different now than I ever really have been. Just I am who I am and I'm OK with that and I love me for me. Just being able to get some of the things out from inside of me that I hid for so long or compartmentalized for so long I think was something that felt good and felt like a weight off my shoulder. From a day-to-day basis I'm usually pretty happy all the time."
Most of the top swimmers in the U.S. are competing this weekend, including Missy Franklin, Katie Ledecky and Nathan Adrian. Typically a short-course yards event, the winter nationals are long-course meters this year in an attempt to give swimmers a chance to reach qualifying times for the Olympic Trials.
If there is such a thing as a home-pool advantage, then it belongs to Adrian, who grew up just across Puget Sound in Bremerton, Washington, and swam in the competition pool too many times to count. Adrian will be swimming the 50 and 100 freestyle.
"This is fun. People are making a big deal of it so it's exciting," Adrian said.