Crews were continuing to search Monday for an Irvine man who became lost while hiking Mount Baldy over the weekend.
Sreenivas "Sree" Mokkapati, 52, and three other hikers set out for the summit from the village at Bear Flats in the early morning hours Sunday, according to a news release from the San Bernardino County Sheriff's Department.
Mokkapati was separated from the group at some point during the trek. His companions contacted authorities after they got back to their car around 4 p.m., investigators said.
Sheriff's officials searched the area in the air and on the ground through the night, but they've been unable to find a sign of Mokkapati, and efforts are ongoing.
Volunteers are also combing through the mountain terrain, and crews from Los Angeles, Orange and San Diego counties have also joined the search, deputies said.
Mokkapati was last seen wearing a gray puffer jacket with gray pants, according to the Sheriff's Department.
Authorities did not say whether the Irvine man had his cellphone, or if he may be equipped with any gear.
Temperatures in the mountain area are expected to be in the 40s Monday night.
Anyone with information on his whereabouts can contact Sgt. Al Huff or Detective Brent Meelker at 909-453-5392 or 909-677-9436. Anonymous tips may be submitted via 800-782-7463 or www.wetip.com.