The search continues for a survivalist father accused of killing his three daughters and vanishing into the wilderness of Washington, as the investigation extends beyond a month. Local authorities express their growing frustration as the search efforts yield few results.

“I’m still angry,” stated Chelan County Sheriff’s Deputy Mike McLeod in an interview with USA Today, reflecting on the hunt for 33-year-old Travis Decker. “He remains at large.”

Decker, who previously served in the U.S. Army and acquired survival training, is suspected of murdering his three daughters – Paityn, 9; Olivia, 5; and Evelyn, 8. Their mother, Whitney Decker, reported them missing on May 30 after the girls failed to return from a court-ordered visitation with their father.

The U.S. Marshals Service remains the lead agency in the four-week-long hunt, working alongside SWAT teams and local law enforcement. 

“You have to be responsible with your financial resources,” Morrison said. “Which means you have to ask whether you are tracking active leads. Typically, people who disappear want to live in more populated areas where they have access to supplies.”

At the time of the girls’ deaths, Decker was homeless, living between motels and campground sites while suffering from mental health issues, according to court documents. He is charged with three counts of aggravated first-degree murder and kidnapping. 

The Chelan County Sheriff’s Office did not immediately respond to Fox News Digital’s request for comment. 

Decker is described as a white man standing 5 feet, 8 inches tall, and weighing approximately 190 pounds. Authorities warn that he is considered armed and dangerous but insist they have no reason to believe Decker is a threat to public safety.

The U.S. Marshals Service is offering a $20,000 reward for any information leading to Decker’s arrest.