The medical examiner's office said 70-year-old Paul Yoon died of cranial and cervical spine injuries on Sunday.
His friends said he was very active with hiking and cycling and loved playing ping-pong.
But they also told KITV they witnessed him slip and fall a number of times during his 10-month membership with their hiking club.
"No trail is worth dying for," said Department of Land & Natural Resources director William Aila.
It's the higher than a bird's-eye-view of some of the most stunning sights on earth.
The lure of Hawaii's lush and majestic hiking trails is attracting more people and risking more lives.
"The mountains are very friable. They are eroding and so you have a narrow path and people need to understand it really may not be all that stable," said Aila.
On Sunday, 70-year-old Paul Yoon was hiking Mariner's Ridge Trail with the Honolulu Korean Hikers Club.
Witnesses said the group reached the top, then, went off the beaten path, when Yoon slipped and fell about 30-feet.
He died on the way to the hospital.
"The whole thing happened in slow motion. I remember seeing her go over, and seeing her face while she was going down the side," Aaron McClendon.
On Saturday, he said his friend 23-year-old Elizabeth Tarpey slipped on a loose patch of soil and fell 300 feet off the Pu'u Manamana hiking trail in Kaaawa.
It took rescue crews five attempts to reach her on the jagged, dense mountain side.
"This isn't an isolated thing. This is becoming more and more frequent," said Kauai Fire Capt. Sam Lee.
The day-long rescue in April of more than 50 hikers on Kauai's Kalalau Trail highlighted the increasing calls and dangers to crews.
Aila said that hunger for outdoor excitement is fueled by the endless clips and pictures online.
"I think the difference between now and 10 years ago is that there are more people that want to do extreme sports and you take the risk if you do that," he said.
At the time of their accidents, Aila said Yoon and Tarpey, were both on parts of hiking trails not sanctioned or maintained by the state.
The medical examiner said Tarpey died Sunday of multiple internal injuries.
Her parents flew in from the mainland.
Yoon is survived by his wife and two daughters, who are also arriving in the next day or two.