While there was no sign of Sreenivas "Sree" Mokkapati, the rescue crews came across four other hikers who had been stranded in the snow or injured.
"It was heartbreaking to find out it wasn't my father," said Shravan Mokkapati, the hiker's son. "But I know the volunteers are doing their best. They're doing whatever they can to help find my father."
The number of certified search-and-rescue volunteers that are available to take time off from their jobs to help with the search has dwindled since it began. More teams are expected to arrive from Fresno and Northern California.
San Bernardino County Sheriff's Department deputies are warning other hikers that conditions have gotten dangerous on the mountain. Even when there is no snow at the base of the mountain, up at higher elevations it's a much more dangerous situation, they say.
A candlelight vigil was held Wednesday night in Mokkapati's honor.
"Bring him home safely," his son said. "We all are praying he's somewhere up in the mountains safe, taking shelter."
Mokkapati and three other people went hiking Sunday, from the Village at Bear Flats to the Mount Baldy Summit.
During the hike, the 52-year-old Mokkapati became separated from the group, according to the San Bernardino County Sheriff's Department. Friends alerted authorities once they arrived to their car.
Shravan says his father is an experienced hiker and goes on Mount Baldy on a regular basis. But he was only prepared for a day hike, not four days in the snow.
"We do think Sree, because of his strong spirit, the way he is, he's able to survive for a little while," said a friend, Luc Lemans
Friends say Mokkapati was last seen wearing a gray puffy jacket and gray pants.
Anyone with information regarding the search is urged to contact the San Bernardino County Sheriff's Fontana station.