SIOUX FALLS, S.D. (AP) As the annual Sturgis Motorcycle Rally turns 74 this year, the Black Hills is bracing for as many as a half-million bikers rumbling through the region - many of them with the creaky knees, portly midriffs and graying manes that mark them out as members of the Baby Boom generation.
Organizers love their older riders, but with an eye on the future, they're making moves to attract an adrenaline-loving younger breed of riders. They're bringing in pro racers Ben and Eric Bostrom, opening up a drag racing course and staging an area of vendors and demonstrations that target the energy drink crowd.
''You've got to keep replenishing the blood to keep it going,'' said Tammy Bohn, who's in charge of the motor sports geared toward younger riders. ''I'm bringing in the young `uns.''
The Sturgis rally drew 466,000 people last year. This year's edition, which starts Monday and runs through Sunday, is expected to do even better based on reservations and inquiries, said rally director Brenda Vasknetz. A survey of riders has suggested the event's economic impact on the state is as much as $500 million, Sturgis city manager Daniel Ainslie said.
But the ridership is aging, Vasknetz said. Rally-goers don't have to register, but she said the average attendee is 45 to 65.
''As our demographics are aging, we are looking at new things to do to entice the younger generation,'' she said.
The highlight of the youth effort is several events featuring the Bostroms, known as the ''Boz Bros.''
On Tuesday, the brothers will invite riders on any kind of vehicle to race on the Sturgis Dragway. ''From mini bikes to golf carts, the drag course is going to be open for a good time,'' Eric Bostrom said. ''If you want to make a bet with your buddy about who can get to the end of the drag strip, that's great.''
On Wednesday, the Bostroms will lead a 60-mile ride through the Black Hills.
They're also advocates for the Black Hills.
In a telephone interview, Eric Bostrom praised the peaks, valleys and curves of the Black Hills for the thrilling rides they offer. He compared the terrain favorably to Florida, where events such as the Daytona 200 can be more attractive to the younger set.
''The area, the geography, is almost purpose-built for us,'' he said. ''It's going to be a good time. That's what a motorcyclist is all about - feeling the highway and taking those curves.''
A series of events are geared at young people, concentrated at Exit 32 on Interstate 90.
Unknown Industries riders Buddy Suttle and Nick Leonetti from the ''Harley Wheelies'' YouTube series will be performing daily freestyle Harley demos. Brammo electric motorcycles, where Eric Bostrom is head development rider, will have a display. So will Monster Energy Drink and Italian motorcycle maker Ducati.
The site will also feature other vendors, music, food and merchandise mostly geared to young people and ''hip, young bike builders that will be showcasing their latest masterpieces,'' according to the promotional flier.
''It's finally a place where they can park all these sport bikes and hang out,'' Bohn said.
Eric Bostrom said he and his brother last joined their father at Sturgis when they were kids and they look forward to working with rally organizers over the next four years to try to lure younger riders. He expects the real growth to start showing up next year as word spreads among their fans.
''I've had a huge response on social media. And a lot of people are saying, `I wish I would have seen it sooner so I could have scheduled it.' That tells me the event is going to grow for 2015,'' he said.
Contact Carson Walker at https://twitter.com/carsonjw