Seemingly less penal rough and improved driving are fuelling Cameron Smith's belief he can finally challenge for US Open glory.

Smith has arrived in Los Angeles for men's golf's third major of the year buoyed by his best-ever finish at a PGA Championship, a Sunday 65 rocketing the world No.9 into a tie for ninth at Oak Hill last month.

After closing with a record-equalling 62 at LIV Golf Tulsa the week before, Smith feels his game is trending nicely as he strives for a second major to go with the Claret Jug from last year's memorable British Open triumph at St Andrews.

Spearheading a seven-strong Australian assault at this week's US Open, Smith feels mentally and physically refreshed after a fortnight at home in Florida recharging the batteries.

The rust is also gone after he entered the Masters somewhat underdone from LIV Golf's lighter schedule.

"The last few months, though, we've played a lot of golf," Smith said.

"We've played all around the world and seen a lot of different courses, a lot of different tests. It's actually been really good for the game.

"The last six or seven weeks the game has started to feel like it's really flipped a switch and has started to be in the right direction.

"Two weeks at home, resting the body and resting the mind, was really nice. It was a really busy, stressful time travelling a lot."

Most importantly, Smith is finding more fairways, which has always been the key to the sweet ball-striker cashing in on his short-game wizardry.

The 29-year-old believes the rough at Los Angeles Country Club isn't quite as punishing as traditional US Open set-ups.

"We're used to that kind of really thick, juicy rough. It's a little bit different here," he said.

"The Bermuda rough, you can get kind of lucky or unlucky.

"There's patches out there where they're actually quite thin and you can get away with a bad shot, and other patches where if you're in there it's no good at all."

The US Open has been Smith's least productive major, with the Queenslander missing the halfway cut in three of his previous seven appearances.

But he was tied for fourth on debut back in 2015.

"I'd like to think that I play my best golf around tough golf courses," he said.

"I know my US Open record isn't that great. For me, the driver has always been the one club where it gets me in trouble.

"In the US Open, and probably the US PGA, you have to drive the ball strong.

"That's where a golf tournament can get away from me, but the driver is starting to feel really good, and there's a few opportunities around here to make birdies, so that falls into my hands a little bit."

Former world No.1s Jason Day and Adam Scott, emerging stars Cam Davis, Min Woo Lee and Lucas Herbert, and amateur qualifier Kurt Vilips round out the Australian challenge.

Day broke a five-year winless drought with victory at May's AT&T Byron Nelson before missing the cut at his past two events.

A two-time winner at Riviera Country Club just 11 kilometres down Sunset Boulevard, Scott arrives in LA with three top-10 finishes in his past four starts.

Like Smith, Davis shot 65 in the final round of the US PGA to record his best finish at a major, while Lee earned a share of 18th having started Sunday tied for 10th.