Human remains believed to be Travis Decker were found after a three-month search for the Army veteran wanted for murdering his three young daughters near a campsite in rural Washington.

The likely body of the National Guardsman was discovered in the Icicle River drainage after officials earlier warned he should be considered dangerous and could be “anywhere within the nation.”

“We are waiting for further confirmation tomorrow,” Chelan County Sheriff Mike Morrison told NCWLIFE Thursday evening, “but it seems to be consistent with (clothing) we believe he was last seen in.”

Official identification will be made by the Washington State Patrol Crime Lab.

The bodies of Decker’s three girls — Paityn, 9 Evelyn, 8; and Olivia, 5 — were discovered with plastic bags over their heads and zip ties around their wrists near Decker’s truck on June 2, three days after he took them for a “planned visitation” from their home in Wenatchee.

Preliminary investigations indicate the sisters likely died from asphyxiation.

Their mother, Whitney, told detectives that Decker, who would now be 33, “was quieter than usual, which was out of character,” when he picked them up, according to an affidavit seen by KOIN.

The couple divorced a few years ago, but at the time, Decker was not homeless, and the separation was civil, according to the affidavit.

But after a deterioration in his mental health and stability in the past two years, Decker’s access to his kids was cut to alternate weekends after a custody hearing several months ago, Whitney Decker’s lawyer, Arianna Cozart, told The Post.

“He’s a broken human, like anybody who would commit such a heinous act is, you know, I don’t know a better way to put it,” she said, claiming that Decker had received little help after he left active duty for the US Army Rangers and had sought out emergency services for veterans.

“What Whitney believes is that the girls would still be alive if our veteran system and the resources, the mental health resources available to our veterans, was adequately funded. There is not one instance that shows that Travis did not love those girls and was not a loving, active father.”

Decker had apparently searched online “how to relocate to Canada” and “jobs Canada” at least a week before he vanished with his daughters, new court papers revealed.He also visited the Canadian government’s “Find a job” webpage on May 26.

The girls’ remains were discovered only 11 miles away from the Pacific Crest Trail, which leads directly to Canada, Deputy US Marshal Keegan Stanley wrote in an affidavit, adding that there’s reason to believe Decker was fleeing to avoid prosecution.

Decker was thought to be hiding out in the wilderness in Washington, using outdoor survival skills he learned in the military, police told a news conference Wednesday.

Remote areas throughout the state have since been temporarily closed as multiple agencies continue their manhunt, according to authorities, who issued a $20,000 reward for information leading to the alleged killer’s arrest.

Decker previously attended mountain survival school and often lived out in the wild for months at a time, his father told detectives.

“It sounds like at times he would go out and would be leaving off grid for sometimes up to two and a half months, so we understand that that’s a possibility, that he could have scoped out this area before, put supplies out there and has the ability and the knowledge to survive for a long period of time,” Chelan County Sheriff Mike Morrison told reporters.

Whitney Decker is now calling for a change to Washington’s Amber Alert system, which she believes could have played a crucial role in finding her daughters alive.

“It’s very important to Whitney to get that fixed,” said Cozart, who represented Decker during her three-year custody case with her ex-husband.

Whitney Decker believes the decision by the Washington State Patrol not to issue an AMBER Alert in the critical hours after she first reported her children missing made all the difference, Cozart said.