Despite the decreasing number of days before the NorthShore Inline Marathon, executive director Skeeter Moore’s to-do list keeps expanding.

“I just added another page,” Moore said incredulously Tuesday.

Moore and his NorthShore staff have a party to plan - the 20th anniversary of the nation’s largest inline marathon, which goes off Saturday from Two Harbors to Duluth.

As of Tuesday afternoon, about 1,115 had registered for the 26.2-mile skate, with another 800-plus entrants spread across accompanying races, including the inline half-marathon, wheels-off half and the Tunnel 10K.

All have become a mid-September staple along Scenic Highway 61 and into Canal Park.

Humble beginnings greeted the event’s 1996 debut. That quickly changed. Just a year later, the NorthShore Inline Marathon had morphed into the biggest event of its kind in America.

Approaching its 20th birthday, it has yet to relinquish the title.

“It’s a world-class event,” race director Tone Coughlin said. “The first year there maybe were some domestic pros, but now we’re international and it didn’t take long for the race to get international.”

Underscoring that point, Coughlin alluded to the “fastest man on skates,” Bart Swings, trekking to Duluth this weekend all the way from Belgium.

Other headliners include world champions Brittany Bowe and Jorge Cifuentes, as well as national champs Justin Stelly, Kelsey Helman and Norm Kirby.

Moore says the notoriety of the race, plus a second-to-none, point-to-point course that combines spinning alongside Lake Superior and through interstate tunnels, as reasons for the global appeal.

“When can you go on I-35 without carrying a gas can or a flat tire?” Moore asked.

Save for the addition of a few races - most notably, the running ones - the NorthShore Inline Marathon hasn’t strayed far from the roots established by event founder George Hovland.

It’s still a get-together for skaters of all abilities, it still relies on overwhelming community support and it still showcases the world’s best.

Moore credits Duluth and Two Harbors, along with St. Louis and Lake counties and the Minnesota Department of Transportation for working together to annually create a near-flawless race-day experience.

Back in 1996, the country’s largest inline marathon was the well-established Athens to Atlanta Road Skate, Coughlin said. For a man who skated the inaugural race, he remains surprised the NorthShore grew as rapidly as it did.

“I’m surprised that it did turn into the nation’s largest; I’m not exactly sure why it did,” Coughlin said. “The sport was growing so fast, but I guess I never thought it’d grow to where it eventually did, and now it’s on the decline. But it’s stuck around and we’ve always had the biggest race.”

It topped out at 4,384 registrants in 2002.

Coughlin likes to look back and recall the evolution of the NorthShore, including “the tailwind year (1998) and the years that it was freezing cold, 18 degrees at the start line.”

Men’s and women’s course records were set in 1998. Chad Hedrick’s mark of 57 minutes, 18 seconds still stands today, as does the 1:10:26 turned in by Heather Gunnin.

In celebration of Year 20, the NorthShore will offer “bounties” of $20,000 (men) and $10,000 (women) for new course records.

* The NorthShore expo goes from noon to 9 p.m. Friday at the DECC.

* The kids sprints begin at 5 p.m. Friday on Harbor Drive, next to the William A. Irvin. They are free. Registration opens at 4 p.m.

* Registration for Saturday races is available online at northshoreinline.com until midnight tonight. In-person registration also can be done at the expo.

* Race officials were uncertain Tuesday whether 2014 men’s and women’s champs Carlos Perez and Franchesca Bell, respectively, would return Saturday to defend their crowns.