SEATTLE — Authorities have closed a wide swath of popular campgrounds and backpacking areas along the Pacific Crest Trail in Washington as they search for a former Army soldier wanted in the deaths of his three young daughters.

Dozens of additional law enforcement officers from an array of agencies joined the investigation and search Friday for Travis Caleb Decker, 32, four days after the girls – 9-year-old Paityn Decker, 8-year-old Evelyn Decker and 5-year-old Olivia Decker – were found dead at a remote campsite outside Leavenworth.

The girls’ mother reported them missing the night of May 30 when Decker failed to return them to her home in Wenatchee, about 100 miles (160 kilometers) east of Seattle, after a scheduled visit.

Gov. Bob Ferguson announced Friday night that he was ordering the state’s National Guard to help with the search, saying “we will be providing helicopter transportation for law enforcement as they search in remote areas.”

“The brutal murder of these young children has shocked our state,” he added in a statement on social media. “I’m committed to supporting law enforcement as they seek justice for Paityn, Evelyn and Olivia.”

The Chelan County Sheriff’s Office said in a statement that there were more than 100 officers involved in the search, which covered rugged terrain in the Cascade Mountains of central Washington, and more than 500 tips had poured in from the public.

“Out of an abundance of caution, we have been given notice to, and are working in conjunction with our surrounding counties in the event Mr. Decker moves through the forest into their jurisdiction,” the statement said.

Decker was an infantryman in the Army from March 2013 to July 2021 and deployed to Afghanistan for four months in 2014, according to Army spokesperson Lt. Col. Ruth Castro. From 2014 to 2016, he was an automatic rifleman with the 75th Ranger Regiment at Joint Base Lewis-McChord in Washington.

Last September his ex-wife, Whitney Decker, wrote in a petition to modify their parenting plan that his mental health issues had worsened and that he had become increasingly unstable, often living out of his truck. She sought to restrict him from having overnight visits with the girls until he found housing.

“He has made huge sacrifices to serve our country and loves his girls very much but he has got to get better,” she wrote. “I do not want to keep Travis from the girls at all. … But I cannot have our girls staying in what is essentially a homeless shelter, at times unsupervised, with dozens of strange men, or staying in a tent or living in his truck with him both in extreme temperatures and unknown areas for their safety.”

Authorities warned people to be on the lookout for Decker and asked those with remote homes, cabins or outbuildings to keep them locked, to leave blinds open so law enforcement can see inside and to leave exterior lights on.

It was unclear if Decker was armed, but the Chelan County Sheriff’s Office said he should be considered dangerous. A reward of up to $20,000 was offered for information leading to his arrest.

An online fundraiser for Whitney Decker raised more than $1 million, and friends Amy Edwards, who taught the girls in a theater program called “Short Shakespeareans,” and Mark Belton thanked supporters during a news conference Thursday.

“Their laughter, curiosity and spirit left a mark on all of us,” Edwards said. “They were the kind of children that everyone rooted for, looked forward to seeing and held close in their hearts.”

Edwards and Belton said Whitney Decker hopes the tragedy prompts changes to the state’s Amber Alert system as well as improvements in mental health care for veterans. The night the girls were reported missing, Wenatchee police asked the Washington State Patrol to issue an Amber Alert but it declined, saying that as a custody matter without an imminent threat, the case did not meet the criteria for one.

The patrol did issue an “endangered missing person alert” the next day, but those do not result in notifications being sent to mobile phones.

As searches expanded for the girls last weekend, a sheriff’s deputy found Decker’s pickup in the area of Rock Island Campground, northwest of Leavenworth. There were two bloody handprints on the tailgate. The girls’ bodies were discovered down an embankment nearby with evidence that they had been bound with zip ties, according to an affidavit filed in support of murder and kidnapping charges against Decker.

County Coroner Wayne Harris said Friday that his office was awaiting pathology results to determine when and how the girls were killed.

Authorities issued closure notices the previous day for that camping area, which lies in the Okanogan-Wenatchee National Forest, as well as for a large swath of rugged territory to the north. That included trails and campgrounds along the Pacific Crest Trail, which runs from the Canadian border to Mexico, and around Stehekin, at the northern end of Lake Chelan.