For much of Collin Morikawa’s life, the Los Angeles Country Club was a mystery.
The course, designed in 1921 by George C. Thomas Jr. with its North Course restored by the architect Gil Hanse in 2010, was off-limits to most — even Morikawa, a son of Southern California and one of its most promising golfers.
But entering this week’s U.S. Open, he is one of a handful of professionals with meaningful experience at the club, which has not hosted a PGA Tour event since 1940 and has never been in the spotlight of a major tournament. Its most recent high-profile competition was the 2017 Walker Cup, an amateur team event played every two years.