Avoid them like a hazard, which is both a concept and the routine golf term that explains the essence and purpose of the idiosyncratic Erin Hills bunkers. They are called erosion bunkers because they have been laid across the uneven, jagged glacial deposits left in a Wisconsin pasture 35 miles west of Milwaukee.
Bunkers at other high-end golf courses are placed like majestic jewels and are filled with fluffy, glistening, almost snow-colored sand. The bunkers at Erin Hills are rough-hewed, a shade of cloudy khaki, and have creepy, slender ribbons of sand that look like the tentacles of alien monsters. They are steep and irregular, and they flow arbitrarily across the landscape like parts of a meandering stream. They are admittedly picturesque — perhaps like works of art, if art can also be menacing.
Erosion bunkers? It is an apt description, if it refers to how they erode the self-assurance of everyone on the course holding a golf club.
The atypical placement of the bunkers was a function of the distinctive topography of the site — hummocks, gorges, hills and dales that slanted and dipped. On Scotland’s seaside, the birthplace of golf, the first bunkers were a result of wind, water and burrowing animals. In modern times, bunkers have customarily been carved out of terrain, often with an earthmover.
“At Erin Hills, each bunker has not been shaped but instead just laid across the slope, and it’s as if the bunker itself eroded right out of the land form,” said Gil Hanse, a prominent golf architect and Fox Sports analyst.
For the players participating in the United States Open, which begins Thursday, the bunkers will add a fickleness to what has been one of the most predictable parts of their games.
The modern PGA Tour-level golfer is so adept at playing from traditional bunkers, where the ball usually sits in a flat or slightly sloped spot, that players will track their errant shots in the air and beg for them to find the sand.
Justin Rose, the 2013 Open champion, said Tuesday: “On tour, it’s a given that in the bunker is a good play. But this week, in a bunker is not a green light. It is a hazard.”
There’s that word again.
This week, those who hit into the bunkers will often find themselves with extreme downhill, uphill or side-hill lies. Their shots will come to rest in the nooks and crannies of the sprawling bunker complexes.
“There are going to be some severe situations,” said Adam Scott, who will be playing in his 16th Open. “It’s inevitable because it’s a severe piece of land with so much undulation. You hope you get a good bounce. You minimize the damage if you don’t — if you don’t lose your patience.”
The bunkers have always been a priority of the Erin Hills design. The course superintendent, Zach Reineking, who has been at Erin Hills since before it opened in 2006, said there were lengthy experiments to find the appropriate sand to put in the bunkers.
The types of sand usually used at other golf courses would wash out of the steep faces of the Erin Hills bunkers after heavy rainstorms, and it would take Reineking’s crews half a day to repair the damage.
After about a year, a sand symposium of sorts was arranged, during which Reineking and other Erin Hills officials tested 20 samples that had varying percentages of ground granite and sand particles — some rounded, some more angular. The group eventually decided on a mixture that has proved to withstand heavy rain and largely mimics the playability of sand customarily found on the PGA Tour.
Players this week have called it consistent, but they have had to make minor adjustments.
“The ball comes out a little more slowly,” Rose said. “You have to generate a little more club-head speed.”
But Jason Day, who has played in six U.S. Opens and finished in the top 10 five times, said the granite particles in the mixture might require players to be more meticulous even outside the bunkers. Day said shots from greenside bunkers deposited the granite, which he referred to as small pebbles, on the putting surfaces.
“You have to really look out for it on the greens,” Day said. “Because it does blend into the greens very well. So a lot of those small pebbles are going to be in amongst or around the hole.”
Yet another hazard.
Golf’s traditionalists are not afraid of that word.
“All in all, good players can avoid bunkers, and the philosophy here was to remind players that a bunker is a hazard,” said the Fox Sports analyst Paul Azinger, the 1993 winner of the P.G.A. Championship. “I think the bunkers here are beautiful.”
Azinger smiled and added: “Of course, I’m not playing this week. That’s why I think that. If I was playing, I’d probably hate them.”