A US rock-climber has fallen to his death shortly after proposing to his girlfriend.

A ROCK climber has plunged to his death shortly after proposing to his girlfriend.

Brad Parker, a 36-year-old yoga instructor, had just completed a hike with his girlfriend at Yosemite National Park on Saturday when he asked her to marry him, his father Bill told the Press Democrat.

When she accepted, Parker told her it was the “happiest day of my life,” his dad said.

Afterwards, the couple separated so he could climb the nearby Matthes Crest, described as a dramatic ridge of upturned rock, 150 metres high, alone and without ropes.

Other climbers reported seeing Parker fall around 5:45pm (4:45am Sunday AEST), Yosemite Park Ranger Kari Cobb said.

“We’re all so stunned,” Bill Parker said. “What happened is so unbelievable.”

He said his son was a capable climber, having graced the cover of California Climber magazine in 2012, guessing tiredness may have been a factor in the fall.

Brad Parker’s friends and family described him as a world traveller who loved the outdoors, including surfing, mountainbiking and fishing.

He was “the best human being he could be,” said Lindsay Ptucha, an old university friend. “He always had this big, big smile.”

“He was all about fitness and spirituality,” his uncle Kit Kersch said. “He did more in his 36 years than most people do in 75 or 80 years of life.”