Small 'stockpiles or campsites' discovered in search for escaped Pennsylvania inmate with survivalist skills, police say

Authorities in Pennsylvania said Sunday they discovered "small stockpiles or campsites" in wooded areas they believe are associated with self-taught survivalist and prison escapee Michael Charles Burham.

Pennsylvania State Police said the discovery was made in wooded areas around Warren, a small city in northern Pennsylvania about 60 miles from Lake Erie.

Authorities continue to search for Burham, described as a "dangerous" inmate with survivalist skills and military experience, who they say escaped Warren County Prison by elevating himself on exercise equipment and using tied-up bedsheets to descend from the roof, according to a county spokesperson.

Police in the city of Warren said Friday in social media posts officials discovered Burham - who was being held on arson and burglary charges and was a suspect in a homicide investigation - had escaped.

Warren police said Burham "was also associated with the prior carjacking and kidnapping of a local couple while trying to escape capture."

Federal, state and local agencies were involved in an expanded search beyond Warren on Saturday as Burham's whereabouts remained unknown, according to an update from police.

Authorities say Burham may be hiding in the woods near Warren, which is about 18 miles from Jamestown, New York. The city is just outside the Allegheny National Forest.

"Pennsylvania State Police have assumed incident command due to geographical jurisdictions and resources as the search expands throughout the county and into areas of NY," the Saturday update posted on Facebook said.

Officials are offering a reward of nearly $10,000 for information leading to Burham's apprehension, including a $7,500 reward from the US Marshals Service and $2,000 from Warren County Crime Stoppers.

State police believe Burham may have obtained a firearm during his escape.

Authorities said Sunday they have no reason to believe Burham has left the county, but law enforcement is constantly reevaluating.

Pennsylvania State Police Lt. Col. George Bivens asked "people nationwide" to familiarize themselves with Burham's picture and to contact police if they believe they've spotted the escaped inmate.

"We ask that anyone who thinks they may see him not approach him," Bivens said at a press conference Sunday afternoon.

Although Burham was last seen wearing an orange and white striped jumpsuit, denim jacket and crocs, he may have swapped out of his prison attire, Bivens has said previously.

In addition to searching on foot and with K-9 units, law enforcement also used all-terrain vehicles, utility terrain vehicles, drones and an aircraft, Warren County spokesperson Cecile Stelter said.

"Right now, I believe that all of the resources are being concentrated on recapture and keeping the public safe," Stelter said. "We do not want people engaging with him in any way."

Residents in Warren County were advised to check their homes and surveillance cameras for any footage taken between Thursday at 11:30 p.m. to Friday at 12:30 a.m. and reach out to police if they see anything suspicious, Stelter said. Hunters should check their game cams, authorities said.

Bivens said during Sunday's news conference it is possible Burham may have received help from one or more individuals.

"We ask residents to be very much aware that they're locking their homes, that they're securing their cars and valuables and that they make it hard for him to acquire supplies, shelter or (a) vehicle to get out of the area," Bivens said.

He added police are hoping the mounting pressure in the manhunt for Burham will work to their advantage.

"We're pushing hard, trying to locate him," Bivens said. "If he's here, he's out here in the woods and we'll continue to push hard."

When reached by phone, a representative from Warren County Prison declined to comment.

Correction: An earlier version of this story misspelled Lake Erie.

CNN's Zenebou Sylla and Jaide Garcia contributed to this report.