A man hiking 9,000 feet up in the Sierra Nevada has told how he was struck by a lightning bolt that blasted away his clothes, burned a hole in one of his shoes and left him with severe burns.

Austrian Mathias Steinhuber, who was hiking the Pacific Crest Trail with his girlfriend and their friend, had an entry wound on his head and an exit wound on his foot after his ordeal, which happened as he was on the peak of the Northern California mountain range, taking a photo.

"It was like in a dream," Mr Steinhuber, 31, said at the University of California, Davis Hospital Burn Centre.

"I woke up. I had blood everywhere, my clothes were ripped apart. At some distance I heard my girlfriend scream my name. My first conclusion was that I probably fell down the mountain."

Mr Steinhuber said he did not remember being struck. While he could see a thunderstorm far in the distance, he said there was no rain or lightning nearby.

He was left with burns throughout his body and was struggling to walk when a helicopter crew rescued him from an exposed peak among the rugged mountains near Donner Summit on Tuesday, the California Highway Patrol Valley Air Operations said.

Somebody told me the odds are higher winning the lottery than getting struck by lightning... I would've rather won the lottery

The couple, from Innsbruck, were visiting a friend, Carla Elvidge, in Truckee, California, near Lake Tahoe.

Ms Elvidge said she, Mr Steinhuber and his girlfriend Kathrin Klausner - all hiking enthusiasts - were going from Donner Summit to Squaw Valley.

Mr Steinhuber was ahead of his friends and had reached the top of Tinkers Knob, a bare peak with sweeping views of the surrounding mountains and the forests below.

"He was taking a picture and the next thing I know, I see this white flash, like an explosion," Ms Elvidge said.

Mr Steinhuber was hurled away and his shoes and all his clothes, including his underwear, were ripped from from his body. The lightning bolt singed his clothes and burned a gaping hole through one of his trainers.

"Somebody told me the odds are higher winning the lottery than getting struck by lightning," Mr Steinhuber said. "I would've rather won the lottery."