STEVENSON, Wash. -- The father of a hiker who has been missing near the Bonneville Dam for five days said he's "still hopeful" that his daughter will be found.

On Tuesday, 38 volunteers and two helicopters continued to look for 24-year-old Katherine Huether, who has not been heard from since she sent a text message to a friend Thursday afternoon. The missing hiker told her friend she would be home by 8 p.m. that night.

Robert Huether traveled from his East Coast home to assist with the search effort.

"We know this isn't easy. It comes home how rugged and difficult this is," he said at a news conference.

He said his daughter is an experienced hiker who was confident in her ability, but said she was probably not prepared to spend several nights outdoors.

"Kate's a strong young woman," Robert Huether said. "There are so many places where she could be. The folks out here are doing their best. We're still hopeful and we'll be out here … for a while, too, trying to help out."

Katherine Huether's father described her as a caring person who traveled in and outside of the United States.

"She did well in school and had an interest in outdoors activities," he said.

Her car was found at the Pacific Crest trailhead Saturday morning and search crews also found a credit card receipt with her name on it Sunday near Table Mountain. Searchers said there's a huge area to cover in the rescue operation.

Skamania County Undersheriff Dave Cox said the conditions Tuesday morning were cloudy with light rain and a temperature of 37 degrees. The snow level was about 800 feet.

"We think we still have a good chance of finding her alive," Cox said Monday night.

About three hours before Katherine Huether left the trailhead Thursday, a woman called authorities and reported a man exposing himself in the area.

The man hasn't been found, and Cox said there's nothing to indicate Katherine Huether might be a victim of a crime. Instead, deputies believe, she is simply lost.

Raw Video: Missing Hiker's Father Remains Hopeful