There will be 2,250 athletes swimming in the Russian River, cycling north Sonoma County roads and running on foot Sunday for the Ironman 70.3 Vineman, an annual half-triathlon that is a qualifier for the world championships.

The Ironman, formerly known as the Half Vineman Triathlon, is being held for a 22nd year and is one of the oldest and most popular of the half-triathlons, said organizer Amy Latourette.

"We sold out in three hours. We are definitely one of the most popular," Latourette said. "Over the years we have built a good reputation. I do registration and I see the same names every year. And the location you can't beat, Wine Country. We are lucky to have that on our side."

The field includes 44 professional athletes, some from as far away as Australia, New Zealand and Germany.

It also is a qualifying race for the Ironman World Championships held at Lake Las Vegas in Henderson, Nev.

The Sunday event is also two weeks before the Vineman, which is twice the distance for the swim, bike race and run over the same course.

The Ironman event begins Sunday at 6:30 a.m. with a swim in the Russian River, followed by bicycle and running events.

The events will occur simultaneously and contestants will fill some roads in the Russian River, Dry Creek and Alexander valleys until as late as 5 p.m.

"We ask spectators not to drive on the roads," Latourette said. "It is difficult enough for the local people to navigate around 2,200 people. There will definitely be a lot of people, it is pretty crowded."

Most of the roads will be open to regular traffic during the event and will be monitored by USA Triathlon workers.

However, there will be one-way traffic on portions of Windsor, Starr, Slusser and Laughlin roads between 8:30 a.m. to 3:30 p.m.

<NO1><NO>The race begins with a 1.2-mile swim at Johnson's Beach in Guerneville at<NO1><NO> 6:30 a.m., when swimmers will go into the water in groups in 18-minute intervals.

The participants from Johnson's Beach will have a 56-mile bike ride. It will take them on River, Westside, Dry Creek and Canyon roads, Highway 128 through Geyserville, Chalk Hill Road, Pleasant Avenue, Shiloh Road, Old Redwood Highway, Fulton Road, Airport Boulevard, Skylane Boulevard and Shiloh and Windsor roads to Windsor High School.

The last of the cyclists will finish at 2:08 p.m., when that course will close.

<NO1><NO>The final leg of the competition is a 13.1-mile half marathon run starting and finishing at Windsor High School. It is a loop that includes Windsor, Reiman, Starr, Mark West, Slusser and Laughlin roads to North Laughlin Road, where runners will turn around and head back on Laughlin, Slusser and Mark West Station roads to finish at the high school.

The course for runners will close at 5:08 p.m.