An unofficial slogan for the Long Bridge Swim used to be “from ages 8 to 80,” not dissimilar from, say, something you’d find on a board game box.

After this year, however, that slogan might need a change.

The 25th annual Long Bridge Swim features participants of all ages ranging from 9-year-old Sierra Zuberbuhler to the swim’s first-ever nonagenarian in Chuck Milton.

While both the youngest and oldest participants have different backgrounds, both decided to sign up for the Long Bridge Swim through race director Jim Zuberbuhler, who just so happens to be Sierra’s father.

For Sierra, deciding to do the swim was as simple as boldly proclaiming to her dad that she wanted to do it ­— first on a drive back from a white-water kayaking excursion, and then this past January in the Panida Theater at the Banff Mountain Film Festival. Sierra’s confidence in both of these declarations even took Jim by surprise.

Milton, meanwhile, met Jim Zuberbuhler at the Litehouse YMCA. For two days in a row, Martin and Zuberbuhler swam side-by-side (“I couldn’t keep up with him,” Milton recalls) before curiosity got the best of the latter and he introduced himself.

“I told [Jim Zuberbuhler] I was going to go swim this thing and he said ‘Well, I’m the director of it,’” Milton said, with his trademark playful smirk. “Then I said ‘Ooh, I’m swimming with the boss.’”

Since he signed up for the swim, Milton hasn’t changed his routine. He is a lifelong swimmer. For the past 21 years, Milton has made sure to swim every Monday, Wednesday and Friday, marking his mileage on a calendar in order to keep himself accountable (for the record, he is at 2,953 miles).

Zuberbuhler, meanwhile, is starting a lifelong swim of her own. Dabbling in everything from white-water kayaking, to skiing to camping, Zuberbuhler is entering fourth grade at the Sandpoint Waldorf School. During club swim season, Zuberbuhler makes the short walk from school to the Litehouse YMCA every afternoon for practice.

Perhaps it’s the proximity, but she has math class on her mind during long-distance swims.

“Sometimes I forget my times tables, so I have to work on those,” Zuberbuhler said. “After I get to the end of the pool I have to do a flip turn, I’m like ‘Oh no, I forgot which one I’m on,’ and then I start concentrating on how many laps I’ve done. And then I start doing math again.”

“This goes on for a little bit,” she adds, matter-of-factly.

For the first time as a trio, Zuberbuhler and her older brother Maximillian (age 13) will do the swim with their father Jim. Both Sierra and Maximillian are on the Sharks club swim team; according to their father, the sport has them hooked.

Like any endurance sport, swimming is also a mental game; it’s a lonely endeavor. In swims like the Long Bridge Swim, fitness to complete the distance is only half the battle: the other half is deciding to put oneself through it.

Milton and Zuberbuhler aren’t immune to swimming’s mental challenges. Both admit that the decision to sign up and train for the swim has been difficult — Zuberbuhler said she got emotional after she swam out by Dog Beach — yet they have put in the work necessary for a successful swim.

Now all they have to do is finish.

“The key to everything is what you think,” Milton said. “If you think you can do it, you’ll do it.”

Milton, Zuberbuhler and over 700 swimmers will make the 1.76-mile swim across Lake Pend Oreille this morning at around 9 a.m.