The US Forest Service has shut down a large area of wilderness land near where the bodies of three young girls were found earlier this week as authorities continue their search for the girls’ father, who is believed to have killed them on a supervised visitation.

The area around The Enchantments in Washington state’s Cascade Mountain range will be closed until June 18 while investigators search for 32-year-old Travis Decker.

The closures include nearly 20 campgrounds and trailheads near where Decker’s truck, and the girls’ bodies, were found on Monday.

Paityn, 9, Evelyn, 8, and Olivia, 5, left with their father Friday afternoon for what should have been a few hours of visitation, as CrimeOnline reported. Changes in Decker’s behavior resulted in loss of overnight visitations, but he still had visits during the early evening hours on Friday and during the day on Saturday and Sunday every other weekend.

But this time, he did not bring the girls home Friday night, and their mother was unable to reach him. The Washington State Patrol didn’t issue an Amber Alert after she reported them missing because they didn’t think it reached that level of concern but did issue an endangered missing person alert.

“He was an engaged father. He did have some limitations on his parenting time due to his mental illness,” Arianna Cozart, a lawyer for the girls’ mother, Whitney Decker, said.

Decker left the US Army a year ago, Cozart said, but shortly afterward became homeless, living in campgrounds and hotels, his truck, or sometimes the National Guard Armory.

When Whitney Decker sought changes to their custody agreement last year, she cited his stays in the armory with his daughters sleeping on mattresses as well as changes in his behavior. A judge ordered him to receive counseling, but he apparently refused.

“She [Whitney Decker] really feels that the system let her children down. It was the inadequacies in the services for our veterans that killed those children. That’s it,” Cozart said.

Officials are asking residents and cabin owners in remote parts of several counties to lock their doors and be vigilant for any signs of Decker — but not to approach him if he’s spotted.

“We are unsure if Mr. Decker is currently alive, so we are taking it that he is still out there,” Chelan County Sheriff Mike Morrison said. “We will not rest until we’ve located him, whether he’s alive or he’s dead, we want to make sure he’s brought back.”

A $20,000 reward has been offered for information leading to Decker’s arrest.

[Feature Photo via Whitney Decker/Facebook]