The bodies of his father and 9-year-old sister were found inside the submerged vehicle on Sunday and his mother's body was found last Friday. The bodies have been identified of that of Sandeep Thottapilly, 41, and his daughter Saachi, nine, who along with his wife, Soumya, 38, and son Siddhant, 12, went missing 10 days ago.
The family were on a road trip to OR and were returning to their home in California, when they went missing.
The crash site is about 200 miles (322 kilometers) northwest of San Jose. The personnel comes from more than a dozen agencies, including the Marin County Fire Department, Southern Marin Fire Department, Kentfield Fire District, Hopland Fire Department, Rescue Solutions, Piercy Volunteer Fire Department, Leggett Volunteer Fire Department, Humboldt County Sheriff's Office, Humboldt County Search & Rescue, Napa County Search & Rescue, Southern Humboldt Technical Rescue Team, Little Lake Fire District, Mendocino County Search & Rescue, Cal Fire, California Highway Patrol, Graton Fire Department, Santa Rosa Fire Department, Sonoma Valley Fire Department, Shasta County Sheriff's Office and Shasta County Search & Rescue.
A poster shared by friends and family on Facebook said their last known location was the "Klamath-Redwood National Park area".
The Klamath River and a string of parks lie along Highway 101, north of where motorists saw the SUV fall into the river.
The family had gone missing while travelling to meet with family members in San Jose, California.More news: Ronaldo, Marcelo, Ramos others celebrate Champions League victory
It says the vehicle was encased in sediment but that divers were able to feel a person inside the auto.
The searches last weekend involved 70 people, including 21 in the water using Jet Skis and kayaks.
The driver apparently had pulled off the road during a powerful storm but the SUV went over the edge of an embankment into the flooded river, sheriff's officials have said.
Farther south, authorities were still looking for the missing members of a different family whose SUV plunged off a towering ocean bluff along the Pacific Coast Highway last month. In that case, Jennifer and Sarah Hart and three of their six children were found dead at the scene and three other children remain missing.
Soon thereafter, search divers entered the water and were able to feel what they believed to be a person inside of the vehicle.
Five bodies were found March 26 near Mendocino, a few days after Washington state authorities began investigating the Harts for possible child neglect. A body was pulled from the surf April 7 but has not been identified.