Wednesday was a practice day for the competitors preparing for this morning's start of the U.S. Women's Open at Oakmont Country Club. But for the 2,900 volunteers who will be working to make the event run smoothly, it was showtime.

"We're in full operation," said Michael Dixon, director of business operations for Bruno Event Team, the Alabama-based company that is coordinating the non-golf activities associated with the Open. "We did the same things today that we'll do tomorrow. The core of the volunteers that are here are doing the jobs that they're going to be doing the next four days."

More than 1,000 of the volunteers serve as marshals, standing along the fairways, tees and greens, controlling the crowd and signaling for silence when the golfers are hitting. Hundreds of others work in the merchandise tent, transportation and ticketing.

"In a lot of ways, it's a good orientation," said Mr. Dixon, of Robinson. "On-the-job training for them to get out here before the actual competition starts. The volunteers really are the core of the operation. We have almost 3,000 of them, and they play a large, large role in operating the event."

One of the factors that promises to make things go smoothly is that almost half of the volunteers this year were working at Oakmont in 2007 when the men's U.S. Open was played there.

Katherine Thigpen, volunteer manager for Bruno Event Team, said some of the volunteers have been working events at Oakmont for years.

"In those instances, I can't tell them what to do. They know it all," she said. "We have marshals who were here on these same holes when the Open was here in the '70s. That's a huge help for us. They have the familiarity. We're not reinventing the wheel here. We used the same blueprint as in '07."

"There's a great tradition of volunteering here in Western Pennsylvania," Mr. Dixon said. "This is my third major I've worked on, and I've been overwhelmed by the support the volunteers give in this area. It's a very easy recruiting process."

The call for volunteers for an Open goes out more than a year before the event. The first invitees are those who have worked events in the past and have expressed a desire to do it again.

Most of the volunteers at Oakmont will be from Western Pennsylvania, but there are volunteers from 40 states and Canada. Ms. Thigpen said some families plan their vacations around the Opens because they enjoy the role and it gives them a chance to see some of the nation's most beautiful and exclusive golf courses.

And while they're called "volunteers," they actually pay $125 to come out in the heat and work.

There are perks. Each volunteer gets two shirts, a jacket, a hat, a pin, a water bottle, meals on the days that they work, and a weeklong pass. Some of the local businesses give volunteers discounts. And there's a party for them before the start of each Open.

The volunteers work four- to five-hour days with lots of rotation, plenty of water and sunscreen. Shuttles are provided to get them from site to site.

Samantha Allison, 23, of Squirrel Hill, a law student at Duquesne University, said she decided to volunteer because she loves golf and saw some of what was involved at the men's Open at Oakmont in 2007.

"I get in for free. I get to see the players. And you get a good parking spot," said Ms. Allison, who will be a ticket-taker outside the merchandise tent for four days. "It's a good time. The heat's going to bother me, but I caddy in the summer, so I know how to deal with it.

"Plus, all the people are nice. It's a golfing crowd. They're pretty calm."

Roger Townsend, 77, of Wexford, a retired sales manager with J&L Steel, said he decided to volunteer when the senior men's golf club he belongs to put out an invitation.

"All I'm doing today is keeping an eye on things," he said from the comfort of a folding chair in the shade of a scoreboard near the ninth hole. "But during the tournament, whenever they're ready to putt, we put our hands in the air to keep the crowd quiet."

Grant Rauterkus, 12, of the South Side, and his brother, Erik, 15, volunteered through The First Tee of Pittsburgh, an organization operating out of Schenley Park Golf Course.

"I'm going to be doing program sales on Friday," said Grant, a seventh-grader at Obama Academy in East Liberty. "I'm doing it because I really enjoy golf and I love the atmosphere."

Ms. Thigpen, of Laurinburg, N.C., said she came to Pittsburgh two years ago to begin work on the Open. She and her volunteers are braced for large crowds, the biggest turnouts expected on Friday and Saturday.

"Friday will be the public's last chance to see the whole field, everybody. After Friday, some of the golfers won't make the cut," she said.

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