A 20-year-old woman went missing while hiking with her boyfriend in Oregon — and authorities said Thursday they found “some interesting items and clues” while searching for her.

Allyson Watterson and her boyfriend Benjamin Garland, 21, were hiking in a wooded area about 18 miles outside Portland on Sunday when he claims the two became separated, according to ABC News.

Garland was later found sleeping in his truck by a resident. He returned to the hiking area with his father to search for Watterson, but couldn’t find her, the report said.

The boyfriend and his dad then notified Watterson’s family, who reported her missing on Monday.

Garland was later arrested on several charges not related to the disappearance of his girlfriend, the report said.

Since then, trained search and rescue teams have fanned out across the area looking for Watterson — even on Christmas Day.

On Thursday, when the new discovery was made, an Oregon National Guard helicopter with heat-sensing cameras was being used to aid the search.

“[We] have found some interesting items and clues that we’re going to try to find out more information tomorrow with a different type of search,” Washington County Sheriff’s Deputy Tony Morris said at a press conference.

“I’m not free to say what it is at this point. Just know that it’s something that’s going to change the type of searching we’re doing.”

Watterson’s parents were grateful for the search efforts.

“We just really, really want to thank everyone, and we want this to keep going until we find Allyson,” her father, Alan Watterson, said at the press conference.

Her mother, Misty Watterson, said, “She’s just a very special person, and I will do anything to get her home. Anything.”