PARK CITY -- Despite infrared technology and an army of searchers, efforts to locate a missing skier proved unsuccessful Monday night.

The 22-year-old man from Alta was reported missing at 6 p.m. Monday by family members after he failed to reunite with them at the Park City Mountain Resort.Resort spokeswoman Melissa O'Brien said the man, whose identity was not released, had spent the day skiing with family members. At some point the group split up, and he failed to rejoin them as planned, she said.

Members of the resort's mountain patrol were joined by the Summit County Sheriff's Office Search and Rescue team as well as a search helicopter from the Salt Lake County Sheriff's Office.

The helicopter, equipped with an infrared detection system, can zoom in on body heat in the darkness and can usually pinpoint people who are lost or suspects who are trying to hide.

O'Brien said the search continued until 10:30 p.m. and resumed Tuesday at first light.