Big-rig parking lot. Erector set. Tent city.

Downtown Santa Rosa became all of the above Saturday as a small army of workers prepared Old Courthouse Square and the surrounding blocks for today's first stage of the Amgen Tour of California, which starts and ends at Third Street and Santa Rosa Avenue.

White canopy tents were raised. A giant, red arch was being inflated, one of several that will dot the course. Elsewhere, stage platforms were screwed together. Dozens of spectator barriers were unloaded.

Nearly everywhere was the steady beeping of reversing trucks.

"We're getting them loaded in and getting them out as fast as we can," said Jack Shows, a Tour event coordinator helping guide a Team Specialized 18-wheeler at the corner of Fifth Street and Mendocino Avenue.

On the opposite corner, a crew from the Italy-based Liquigas-Cannondale team unloaded a fleet of bicycles from a U-Haul.

"It's really something how far it's come," team crew member Colby Marple said of the Tour, which is now in its seventh year and has become the nation's top cycling race. Santa Rosa has been a stop in six of those tours, but this is the first time the race has started in the city.

The eight-day event will conclude next Sunday with riders from 16 international and domestic teams having covered 733.5 miles.

Thousands of spectators are expected to clog the downtown area today to watch the start, middle and end of the 115-mile trek that extends to Windsor and Highway 1, and to participate in the accompanying festival.

Tour organizers and Sonoma County hospitality industry professionals have projected the event will pump $6.8 million into the local economy as hotel rooms, restaurants and shops fill with teams, sponsors and race fans.

Preparations this year have gone forward with barely a hitch, despite it being the first time the city has hosted both a stage start and finish, said Raissa de la Rosa, a Santa Rosa economic development specialist who led the local organizing committee.

"We are all set to go; it was remarkably smooth this year," de la Rosa said. "It's bigger, but smooth."

Last year was the first time the Tour skipped Sonoma County. This year's start and finish stop was a coup.

"I love watching it," said David Finkelstein, getting ready to board his blue beach cruiser bicycle.

The route goes past his A Street home and afterward, he said, he'll ride downtown for the party. "The people, the businesses, it's great for everyone," he said.

De la Rosa wouldn't venture a guess about how many people will flood the downtown — "I have no idea; a lot," she said — but previous estimates have been as high as 30,000 to 35,000.

"We love it," said Julie Kawahara, owner of Kindred, a fair trade handicrafts store on Fourth Street that will have triple its normal staff working today.

"It's a lot of work for us, but it's happy work," said Pete Mogannam, owner of the 4th Street Market & Deli, normally closed on Sundays. "The people you deal with are out for a good time."

On Third Street, John and Julie Kiil of Santa Rosa wandered through some empty VIP tents and said that family obligations meant they wouldn't be able to attend the festivities, as they have for every race so far.

"They timed it for Mother's Day," said John Kiil.

"I wish we could be here," said the mother in the equation, Julie Kiil. "We've been in the rain; we've been in the wind," her husband said.

The event has evolved, the couple said. "This is pretty fancy-schmancy compared to a few years ago," Julie Kiil said.

"I remember the first year, everybody was hanging out on the (Third Street) garage with their feet hanging off," her husband said.

"Levi's the best," Julie Kiil said, referring to the hometown hero, Santa Rosa's Levi Leipheimer, the three-time Tour of California winner whose decision to race a month after a motorist knocked him from his bike in Spain, causing him to break his leg, has been a central story of this year's Tour.

"He's incredible," said John Kiil. "What a spokesman for Santa Rosa."

You can reach Staff Writer Jeremy Hay at 521-5212 or jeremy.hay@pressdemocrat.com.