The Army veteran accused of killing his three daughters in Washington state and disappearing into the wilderness for weeks may have been spotted in an Idaho forest, federal authorities said.

The person believed to be Travis Decker, 32, was seen in Sawtooth National Forest, hundreds of miles from the campground where the bodies of his young daughters were found June 2, according to the U.S. Marshals Service.

In a news release Sunday, the agency said the tip came from a family who reported having seen a man matching Decker’s description in the national forest’s Bear Creek area, east of Boise.

The man was described as 5 feet 8 inches to 5 feet 10 inches, wearing a black mesh cap, black gauged earrings, black shorts, low-top Vans or Converse shoes and a cream T-shirt. He had a long ponytail, an overgrown beard and a mustache and a black backpack, the agency said.

He was said to be wearing a black Garmin-style watch.

The Marshals Service warned people Monday not to fly drones in the area and to avoid picking up hitchhikers.

Authorities have described Decker, who was an active-duty member of the Washington State National Guard, as an avid outdoorsman known to go “off-grid” for months.

Law enforcement officers have investigated “dozens and dozens” of potential sightings and tips linked to Decker, but he appears to have been seen only once, nearly a month ago, in the Blewitt Pass area of Washington.

After a report from hikers, a tracking team in a helicopter described seeing a “lone, off-trail hiker” who ran from the aircraft.

Weeks later, on Tuesday, the Chelan County Sheriff’s Office said there was no evidence to suggest Decker was alive or dead.

His daughters, Paityn, 9, Evelyn, 8, and Olivia, 5, were found dead in a remote area near Leavenworth, roughly 135 miles east of Seattle, after Decker failed to return them to his ex-wife. According to an affidavit in support of an arrest warrant, the girls had been zip-tied and had bags over their heads.

An autopsy attributed their deaths to suffocation.

Decker’s pickup was found near the girl’s bodies, and the sheriff’s office said an analysis of bloody handprints on the vehicle’s tailgate matched Decker’s DNA profile.

Whitney Decker was married to Travis Decker for seven years and described their divorce to authorities as amicable, according to the affidavit. The detective who wrote the affidavit noted that Travis Decker refused to sign a parenting plan last year and did not seek court-mandated mental health treatment and domestic violence anger management counseling.

Decker is wanted on charges of first-degree murder and kidnapping. He is also wanted on a federal charge of unlawful flight to avoid prosecution.

According to an affidavit in support of the federal charge, authorities discovered that in the days before the girls’ deaths, Decker appears to have searched Google for information related to Canada.

“How does a person move to canada” and “how to relocate to canada” were among the search terms linked to Decker’s Google account on May 26, according to the warrant. The deputy U.S. marshal who wrote the warrant noted that the victims were found 11 miles from the Pacific Crest Trail, a well-established path that leads to Canada.

The possible sighting in Sawtooth National Forest is more than 500 miles in the other direction.