The Aspen Times reports that Alex Burchetta of the Pitkin County Sheriff’s Office says the man became separated from three others in his party as they descended Pyramid Peak. The man’s name was not released.

Burchetta says the missing man was last seen about 2 p.m. Sunday at about 13,000 feet elevation at the top of a saddle that leads to the northeast summit ridge.

He says officials planned to use a drone Tuesday to help with the search.