When Katie Ledecky arrived in Omaha, Neb., for the Olympic swimming trials, she was greeted by a colossal image of … Katie Ledecky.The two-story Ledecky, grinning down from the CenturyLink Center, reminded the flesh-and-blood teenager from Bethesda, Md., how much has changed for her since she burst on the Olympic scene as a surprise gold medalist in 2012."That's a little different than four years ago," she said. "I took a selfie with it!"Ledecky, 19, might be the only dead-solid lock to win multiple gold medals in Rio de Janeiro. She's so far beyond her competition in the 400- and 800-meter freestyles that only an injury could stop her. She has never lost an individual final at a major international meet.But beyond mere success in the pool, which she's used to, Ledecky is about to experience celebrity on an entirely different scale.Her face will be all over NBC, and casual Olympic watchers will marvel as she wins races by nearly the length of the pool."It's probably a tossup between Ledecky and [gymnast] Simone Biles as 'America's Darling' of the Rio Games," said Bob Dorfman of San Francisco-based Baker Street Advertising. "Ledecky's advantage is that she not only could win four or five golds this year but is still young enough that she could also dominate in Tokyo in 2020 and even be a force in 2024."We've reached a point where no one bothers comparing Ledecky to her contemporary, Missy Franklin, or to the former queen of American distance swimming, Janet Evans.She has left her competition so far behind that only one name comes up regularly when swimming commentators attempt to put her in context.Michael PhelpsAs she repeatedly smashed her own world records and expanded her portfolio to include sprints, comparisons to Phelps intensified.He's often asked about her these days, perhaps because reporters presume one alien is the best candidate to explain another.Phelps responds that Ledecky indeed reminds him of his younger self. It's praise he hasn't offered for any other next-generation swimmer."You can tell she is very goal-oriented, and for me it brought me back to kind of what I was like way, way, way back in the day," he said recently. "You don't really see it — I don't see it that much anymore, and sort of watching how hungry she is and every single day she is going in trying to change something and trying to get better. … It just gives me a lot of, I think, good thoughts of what there is to come in the sport of swimming for the younger kids."They grew up just 45 minutes apart, though in different swimming generations. Just like Phelps, a young Ledecky wrote her goal times on scraps of paper and kept them by her bed. She scored Phelps' autograph when she was a 6-year-old beginning racer, a fun fact to bring up if you want him to roll his eyes at how old he is.Ledecky has modeled her evolving stroke after those of the best male swimmers — kicking steadily throughout her races and breathing only to one side. At trials, she watched video of her younger self on the big scoreboard above the pool and hardly recognized her stroke as a 15-year-old.Phelps, Ryan Lochte and Connor Jaeger have all praised her by noting that she swims, well, like them.Out of the water, however, she's utterly devoid of flamboyance.Phelps always viewed his career in grandiose terms. He wanted to be the Michael Jordan of swimming, to leave the sport permanently changed. And he never minded saying so.Ledecky has no such aspirations."It's not something I've really thought about that much," she said. "Michael has changed the sport, and it's really cool when you get to swim in front of 14,000 people, and I don't know if we would have had that if we didn't have Michael."So just to be on a team with him is a great honor, and to see him go out the way he's going out is really neat. In terms of how I fit into that, I think everybody that's going to Rio wants to represent USA Swimming really well and I think that's our main goal. We've been the best swimming country in the world for, who knows how many years, and we want that to continue."It was a typically self-effacing answer. Ledecky does not talk trash or bubble over with excitement at her achievements. In Omaha, she seemed more thrilled by the swims of her closest American competitor, Leah Smith, than by any of her own victories."If you know Katie at all, it's not surprising to see her react that way," said Bruce Gemmell, her coach at the Nation's Capital Swim Club.Ledecky comes from a high-powered household in the Washington suburbs. Her dad is a Harvard-educated attorney, her brother just graduated from Harvard, her uncle co-owns the New York Islanders. Washington Capitals and Wizards owner Ted Leonsis is a family friend.She's headed for Stanford after the Olympics.But there's never a hint of snobbery to anything she says. Perhaps that's why the people she beats have such nice things to say about her.Phelps' longtime coach, Bob Bowman, and Bowman's successor at the North Baltimore Aquatic Club, Erik Posegay, have both prepared swimmers to take on Ledecky in her signature events.Both make the Phelps comparison without any nudging."She's just like Michael in the sense that she comes in to get better every day and never takes a step back," Posegay said.He doesn't talk to his middle-distance swimmers about trying to topple her."They understand she's a generational swimmer," he said. "But she's such a nice person that honestly, she's fun to compete against."Before the Olympic Trials, Bowman acknowledged what a long shot it would be for Allison Schmitt to beat Ledecky in the 400-meter freestyle, an event in which Schmitt won an Olympic silver medal four years ago."At 400 meters?" he said. "That's a tall order. I don't know that there's anybody on the planet who could beat her right now. It's kind of like Michael in 2004. Nobody was going to beat him in the 400 IM, no matter what."Ledecky will be favored to win freestyle gold from 200 meters to 800 meters and would also be an overwhelming choice at 1,500 meters if women swam that race in the Olympics. The sport has never seen a swimmer so good at such a range of distances.What she lacks, compared to Phelps at least, is mastery of multiple strokes. At his peak, he was elite in freestyle, butterfly and backstroke. She's only a threat in freestyle, though she might attempt the 400-meter individual medley in future Olympic cycles. Because of this, she'll be hard-pressed to chase his total medal counts.Even Phelps, however, never won by the margins that have become common for Ledecky in her best races."Obviously Michael dominated, but not by the amount of time, just from the clock standpoint, that Katie has," said NBC analyst Rowdy Gaines. "Now, her events are longer, especially when you get to the 800, but it really is — I just — I'm at a loss for words sometimes when I think about what she has been able to do the last four years."childs.walker@baltsun.comtwitter.com/childswalker