The story of a man who proposed to his girlfriend and then tragically fell to his death.

When Brad Parker’s girlfriend accepted his marriage proposal at the top of a picturesque mountain on Saturday, he thought it was ‘the happiest day of his life’.

But the day turned to tragedy when Mr Parker, a 36-year-old fitness fanatic, set out on a celebratory climb without his fiancee that same evening.

The yoga instructor and keen world traveller scaled a granite crest in Yosemite National Park, California– but plunged to his death from the rock at about 5:45pm as horrified climbers looked on.

His father told the Press Democrat that Mr Parker was a careful and capable climber, but may have been fatigued at the time of the fall.

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

He added that his son had called after the proposal to say the day was the happiest of his life.

Mr Parker, an experienced climber who appeared on a cover of California Climber magazine in 2012, had reportedly run three miles prior to the fatal climb on Matthes Crest.

He did not used ropes to climb the crest, which reaches about 150 metres tall and is described on website Summit Post as ‘one of the more difficult peaks in the park’.

Sarah McKay, a friend from the climbing centre Mr Parker frequented, described him as ‘an amazing human being’.

“Eternally positive, always putting out this vibe of good juju…. His whole life was about getting out and enjoying the world,” she said.

Mr Parker’s uncle, Kit Kersch, agreed he was ‘all about fitness and spirituality’.

“He did more in his 36 years than most people do in 75 or 80 years of life,” Mr Kersch told the Press Democrat.

Mr Parker had been dating Ms Dial, a yoga instructor and digital media producer from Utah, for just over a year, his friend Jerry Dodrill told NBC Bay Area.

“He was the nucleus of a community of adventurous people out here,” Mr Dodrill said.

“He was a bad ass rock climber and surfer… And he did it all with grace and dignity.”

Mr Parker said he and his wife Gayle had accepted advice not to view their son’s body, which was retrieved from under the ridge, by a helicopter on Sunday morning.

The family are making arrangements to cremate the body, and are planning a hike in the national park with two friends to get some closure, according to the Press Democrat.

A service for Mr Parker will be held in a local park on Saturday and local surfers are also planning a “paddle out” to honour their lost friend, forming a circle on their boards on a local river.