Travis Decker search: FBI conducting investigation at campground where 3 daughters were found dead

(NEW YORK) — An FBI investigation has prompted the closure of several roads, trails and campgrounds in Leavenworth, Washington — including the site where Travis Decker allegedly murdered his three daughters — as the search for the fugitive father nearly reaches the three-month mark, according to the U.S. Forest Service.

In an order posted over the weekend, the U.S. Forest Service said “all of” the Rock Island Campground, along with two other campgrounds, will be closed to “allow the FBI to conduct an ongoing investigation.”

The Seattle FBI office and the Chelan County Sheriff’s Office did not immediately respond to ABC News’ request for comment, but the search area overlaps with where Decker’s truck and the three girls’ bodies were found.

Paityn Decker, 9; Evelyn Decker, 8; and Olivia Decker, 5, were found dead near the Rock Island Campground in Chelan County, Washington, on June 2, after they left home for a planned visit with their father on May 30, according to police.

The closure began on Sunday morning and will be in effect until Wednesday at approximately 6 a.m., officials said. A list of several roads, trail heads will also be closed off to the public, officials said.

Everyone will be prohibited from entering the closed areas except “any federal, state or local officer or member of an organized rescue or fire-fighting force” or anyone with a U.S. Forest Service permit allowing access to “roads, trails or areas restricted by regulation order,” the forest service said.

The closure of this campground comes one week after the Chelan County Sheriff’s Office released disturbing new details about the crime scene and the DNA evidence that they say indicates Decker, a 32-year-old Army veteran, is the sole suspect.

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

Officials said anyone who sees Decker or knows of his whereabouts should call 911 immediately and not contact or approach him. He is currently wanted for three counts of first-degree murder and three counts of kidnapping, officials said.

Decker is considered armed and dangerous, officials said.