Jakson Kreiser, 19, is a first-year employee at the park. He was due to arrive at the Lake McDonald Lodge on Saturday night. When he didn't appear, a park employee alerted authorities.
Park rangers found Kreiser's vehicle at the Logan Pass Visitor Center parking lot. They believe he was planning a day hike from Logan Pass to the Avalanche Lake area.
A search team of about 50 people have been looking for Kreiser by ground and air. The search began Sunday.