What started as a trickle of fans making the trek across the bridge that connects holes two through eight at Oakmont Country Club quickly transformed into a full-fledged bottleneck at the entrance as people kept pouring in from different directions yesterday during the first round of the U.S. Open.

As soon as Phil Mickelson nursed his putt into the cup for a bogey at No. 1, his 10th hole of the round yesterday, fans scrambled toward the bridge that overlooks the Pennsylvania Turnpike between the Monroeville and Allegheny Valley exits. The bridge, constructed in 2003, is used by spectators only, with players and VIPs with badges permitted to cross the less-traveled old bridge about 50 yards further down the course.

The steady stream of people was well-behaved and walked at a leisurely pace until the huddled masses ground to a halt and waited their turn. It took about 10 minutes to make the crossing. The stragglers at the tail-end of the line probably did not get over in time to see Mickelson and the others hit their tee-shots at No. 2.

When the group behind Mickelson's threesome completed No. 1 and strolled over the player's bridge, a smattering of fans briskly made their way across the spectators' bridge.

Earlier in the afternoon, long after the crush of people trying to catch a glimpse of Tiger Woods and long before the anticipated traffic jam expected to follow Mickelson, the flow was brisk.

"If the bridge had not been constructed, we probably wouldn't be here today," said David Fay, the executive director of the United States Golf Association. "That's how important it is in terms of the gallery flow. If you were here in '94 [for the U.S. Open], it was gridlock alert going from one to two and eight to nine. Thanks to the generosity of the Oakmont membership, the bridge was constructed. The bridge was vital in bringing an Open back to Oakmont."

The spectators moved in orderly fashion yesterday, three or four deep heading across the bridge from No. 1 to the other side of the Turnpike, where they faced the well-bunkered fairway and green of the 8th hole. There also were rows two abreast on the bridge returning to the rest of the course.

"This is about as light as it's been since I've been here today," said security guard Rob Krogh, who was hired this week by the Andy Frain Services Security Company. "Mostly, I'm here to answer questions and give directions. be a presence, I suppose."

Krogh, 26, a social studies teacher at Penn Hills High School, was one of the approximately 600 people hired by the company this week.

When asked why he signed up for this job, Krogh answered without hesitation, "For the money." He laughed. "I don't really care about golf."

The bridge was packed just once during his 1-7 p.m. shift, after Mickelson completed No. 10, the starting hole of his round, and headed to No. 11.

"I think maybe people got confused and thought he had played No. 1 and were trying to get to No. 2," Krogh said, with a smile. "It seems like most people follow the crowd before they ask directions. The bridge was jam-packed for about 30 minutes, with stop-and-go movement. My guess is the bridge can hold something like 1,000 people."

Krogh changed his post later in the afternoon and was stationed at the entrance of the bridge for the players.

"At least on that bridge, I'll get to see some players and have something to take home. I'll be able to say, 'I saw so-and-so,'" he said. Did he see any celebrities walking over the spectator's bridge? "I've just seen some friends."