Three men with walkie-talkies keep watch on nearby buildings, looking for spies. Anyone who approaches the front gate is scrutinized.
If you're not on the list, you can't get in.
Tall fences and tight security make Spaulding Field seem a bit like a military installation. In fact, it is a patch of turf where the UCLA football team holds afternoon practice.
The Bruins, who next play California at the Rose Bowl on Oct. 20, do not want rivals getting a look at special formations or trick plays before the game. Coach Karl Dorrell talks about rogue Internet postings that chronicle "how we practiced, how many throws we made, who ran the football, who's hurt."
Recent news has focused on espionage in the NFL, where the New England Patriots were caught videotaping the opposite sideline, recording hand signals that rival coaches flashed to their defensive players. But spying isn't unique to the pros.
The college game abounds with tales of "skunking" -- intruders dressed as painters, even priests. Practices can be hard to protect, what with boosters, high school coaches and recruits often hanging around.
It is impossible to know how much spying actually occurs, but athletic programs erect fences and plant trees, even hire private security firms, to guard their facilities.
"You could see where coaches get paranoid," said Barry Switzer, the championship-winning former Oklahoma coach who was accused of spying in the mid-1970s. "Everyone's wanting an edge."
Soon after NFL officials punished New England in September -- Coach Bill Belichick and the team were fined a total of $750,000 and the team will lose one or more of its top 2008 draft picks -- the University of Georgia closed its practices. The Bulldogs were preparing to play Alabama, a team coached by Nick Saban, who spent four seasons as Belichick's defensive coordinator with the Cleveland Browns.
Georgia Coach Mark Richt stopped short of making the connection, saying: "We just wanted some privacy . . . probably what happened in the NFL recently brought some awareness that this stuff might be going on."
Coaches are hard-pressed to cite a specific play or game in which the outcome might have been affected by spying. But they can point to a history of rivals who have ignored an NCAA rule on improper scouting.
Before the 1950 Sugar Bowl, the Oklahoma Sooners were preparing to play Louisiana State when they caught a man watching practice through binoculars from behind a nearby house. He was a former LSU player who claimed to be scouting talent for a professional team. Oklahoma Coach Bud Wilkinson doubted his explanation, saying: "I can't believe LSU would do such a thing."
Some 20 years later, an Oklahoma booster allegedly dressed as a painter to get inside Memorial Stadium during a Texas practice. Switzer was a Sooners assistant coach then.
"I knew it happened," he said. Asked about how the plan was hatched, he replied: "That's so . . . long ago, I can't remember."
By 1974, Switzer had become head coach and was accused of spying on Texas again, a contention he seemed to acknowledge in a 1990 autobiography but now denies.
There were no denials from Florida after an NCAA investigation found the Gators sent a graduate assistant to rival campuses each week In the early 1980s. About the same time, according to the Memphis Commercial Appeal, an unidentified man appeared at Notre Dame practices dressed as a priest. It was later believed that he was a gambler looking for inside information.
Last season, a West Virginia student was caught diagraming plays at a Marshall University practice. Police found him carrying telephone numbers for the West Virginia coaching staff.
In addition to spies from opposing teams, coaches worry about a newer form of infiltration. Sportswriters covering practice know better than to write about trick plays, but some bloggers and fans have unwittingly posted such details on the Internet.
They might describe a fake punt the team is practicing, or a double-reverse pass.
"If stuff gets out there, it could be damaging," said Dennis Slutak, the director of football operations at USC. "We're cognizant of that."
The Trojans, who play Arizona on Saturday at the Coliseum, have a reputation for letting big crowds into their practices. An assistant staffs the door with a clipboard, but it is not uncommon to find scores of reporters, family members, high school coaches and boosters at Howard Jones Field on a given weekday.
Coach Pete Carroll doesn't believe visitors get a clear view of what his team is doing from field level. He is more concerned about the vantage point from nearby parking structures and atop the adjacent baseball and track stadiums.
"We kind of know the tricks and feel like we monitor it very well . . . we're doing it subtly," Carroll said.
Other teams are more overt. Many close their practices to all visitors, including the media. Or they restrict access to NFL scouts who travel the country evaluating talent.
At Oklahoma, the athletic department pays for private security officers to patrol its tree-lined field.
The current Sooners coach, Bob Stoops, recently told ESPN.com that he "may have made a big mistake" by practicing in the Louisiana Superdome before the 2003 Bowl Championship Series title game.
"I'm just saying there were too many people to track or keep up with," he said.
That's not a problem at UCLA practices, said Bob Lopez, the director of football operations. Though the Bruins welcome media and immediate family, they try to limit the number of visitors who come through the gate each day.
Lopez and his assistants position themselves around Spaulding Field with walkie-talkies, hurrying into nearby parking structures on those occasions when it appears someone has been watching for too long. They try to memorize faces of everyone permitted inside.
"I can pretty much tell you who everybody is in the stands," Lopez said. "I'm not sure we've ever had anyone spying on us but you'd hate not to be on your guard."
Times staff writers Chris Foster and Gary Klein contributed to this report.