Farmingdale, N.Y. ? Bethpage State Park erected a sign on the first tee to let the public know what to expect. “Warning: The Black Course is an extremely difficult course which is recommended only for highly skilled golfers.”

There was no need to remove the sign just because the world’s best players came by for the U.S. Open.

This sign greets golfers on the Black Course at Bethpage Park.

“We all think of ourselves as highly skilled,” Hal Sutton said Wednesday. “I guess we’re about to find out.”

The charm of this U.S. Open is that it will be played for the first time on a truly public golf course that costs no more than $39 a round. Whether it’s a public course or a ritzy country club is no longer an issue for Tiger Woods or the rest of the 156-man field.

They just want to survive.

“This is every bit as hard as any venue I’ve ever seen,” David Duval said. “If you’re not doing everything good, you’ve got no chance.”

That’s what the Open is all about.

Only a dozen players have finished 72 holes under par in the last seven editions, which is why this major championship stands out as the toughest in golf.

Blend that with a course that has a reputation for being a beast, and it’s little wonder that players are approaching the opening round today with trepidation.

“This golf course is tough on its own,” Paul Azinger said. “The U.S. Open has turned it into a monster. It’s going to be a survival of the fittest in every aspect the fittest mind, the fittest body and the fittest game.”

All signs point to Woods, although that’s the case at just about every major. He has won six of the last 10, and comes into the U.S. Open with a chance to become the first player since Jack Nicklaus in 1972 to win the first two legs of the Grand Slam.

Woods won the Masters in April by building a quick lead on Sunday at Augusta National, then watching the best players fall apart.

The real intimidator this week could be the Black, an A.W. Tillinghast design at the world’s largest public golf complex.

“When you’re done here in four days, you know you’ve worked hard,” two-time U.S. Open champion Ernie Els said. “Every aspect of your game gets the test it deserves your mental strength, your scrambling ability, long-iron play, driving ability, everything gets tested. And definitely, your nerves.”

Els won both his U.S. Opens on similar courses 1994 at Oakmont, with its thick rough, punishing bunkers and slick greens; 1997 at Congressional, with its length and tight fairways.

Bethpage Black is the longest par-70 in history at 7,214 yards, with two of the longest par 4s ever at a U.S. Open No. 10 (492 yards) and No. 12 (499 yards).

It that isn’t enough, the USGA will send players off both sides the first two rounds to deal with slow play. That means half the field will start out today or Friday facing a 492-yard hole lined by shin-high rough.

“You’d better be warmed up,” Els said.

And they better find the short grass as often as possible.

Several players say the Black reminds them of Carnoustie, site of the 1999 British Open and the toughest major since the 1974 U.S. Open at Winged Foot. The winning score at Carnoustie was 6-over 290, a combination of high rough and whipping winds.

“With Carnoustie calm, guys can shoot good scores around it,” Nick Faldo said. “But this is the toughest we’ve ever played in calm conditions.”

There is always thick, nasty rough at the U.S. Open, but the USGA must have found a particularly good blend of fertilizer for the Black. There are no patches of thin grass, so no one can expect to get a break by missing the fairway.

Azinger put a 9-wood in his bag for the practice round Wednesday, hopeful it would help him advance the ball out of the rough. Asked if he worried the fairway metal would slide under the ball and lead to a whiff, Azinger laughed.

“You can’t even get under the ball,” he said.

Despite the length on the Black Course, Woods rarely hits driver only five times during his only full practice round on Tuesday, the rest of the time going with a 3-wood or 2-iron.

Woods broke his 3-wood on the practice range Wednesday and had to get it repaired. He’ll need it.

“On most of the courses we play, if you’re 5 yards farther right than you’re aiming, you’re still in the fairway,” Duval said. “Here, you’re chipping out.”

The only break at Bethpage are the greens, and even that is subject to interpretation. The putting surfaces are relatively flat, one reason some USGA officials suggested the 72-hole scoring record could be broken this week.

“There will be a lot of putts made this week,” Sutton said. “For par.”

It all starts to unfold today. Overnight storms were expected to soften the course and make the greens a little easier to hold, although the only thing worse than thick rough is thick, wet rough.

The galleries are expected to approach 50,000 and not just any gallery, either. New Yorkers can be a tough crowd, especially when they’re watching a national championship on a golf course they know better than the players.

Well, maybe not the Black Course in this condition.

“It’s too hard for me,” Scott Hoch said. “I’ve always said I’ve never seen a golf course that I’d sleep in my car overnight to play. And I still haven’t.”