BURNS, Ore. -

The armed activists occupying a national wildlife refuge in southeastern Oregon clashed with environmentalists Saturday as a standoff stretched into a 15th day.

Meanwhile, authorities said a Crescent man arrested Friday for use of a stolen refuge vehicle also faces likely charges for violating a court order to stay off federal property.

Kenneth Medenbach, 62, was taken to the Multnomah County Jail, where he was booked Friday night, according to jail records showing him held without bail Saturday on a "facility hold."

According to The Associated Press, The Oregonian reports (http://goo.gl/yHnphm ) that a shouting match erupted as members of the Center for Biological Diversity, a nonprofit environmental group, tried to speak at a news briefing.

The center's executive director, Kierán Suckling, tried to speak, but the activists screamed and booed him.

Suckling said his group had a more civil interaction with other occupiers afterward. He said it was important to be present and to not criticize the occupation from the sidelines.

Medenbach was arrested Friday by Oregon State Police with one of two vehicles stolen from the occupied Malheur National Wildlife Refuge apparently will face federal charges for violating terms of his release on a previous trespass encampment on federal property in southern Oregon, officials said.

OSP troopers arrested Kenneth Medenbach, 62, shortly after noon at the Safeway in Burns, the Harney County Sheriff's Office said in a news release. He was arrested on probable cause for unauthorized use of a motor vehicle.

The agency said police recovered two U.S. Fish and Wildlife Service vehicles, a pickup truck and a van, "previously reported" as stolen to the sheriff's office.

A spokesman at law enforcement's joint information center told NewsChannel 21 "the vehicles were reported stolen after the situation started" at the refuge. They could not elaborate about the arrest, other than it was only of Medenbach and while he's charged with just one count, two vehicles were recovered.

OSP troopers and deputies from several county sheriff's offices called in to help patrol the area responded to the scene.

"The U.S. Fish and Wildlife Service is grateful for the quick actions from law enforcement," said USFWS spokeswoman Megan Nagel. "We will continue to work with law enforcement to recover vehicles bought and paid for by the American people to care for their national wildlife refuge."

Among his numerous run-ins with federal authorities over the years, Medenbach was arrested last year for camping illegally for months on BLM land near Galice, whre protesters -- some associated with the Malheur refuge occupation -- objected to BLM efforts to enforce an order halting work at a gold mining operation, The Bulletin reported.

His pre-trial release conditions included that he not "reside, camp on, occupy or leave any property on federal lands without the prior written approval of the Court," the newspaper said.

A spokesman at the Harney County Joint Information Center had told reporters late Friday that Medenbach would be taken to the Deschutes County Jail in Bend on the charge of unauthorized use of a motor vehicle. But instead, he was taken to the Portland jail, which also houses inmates on federal charges.

But on Saturday, the spokesman explained to NewsChannel 21, by email, "The conditions of Medenbach's pre-trial release included prohibition from occupying federal land, and judicial authorities are working to hold him accountable for that violation."

"Due to the fluidity of the situation, it would not be appropriate tat this time to discuss his status," he added.

A March 2014 article in The Bulletin said a La Pine-area property on U.S. Highway 97 had Medenbach, "known locally as the wood carver," as its longtime tenant but he had recently vacated the property.

He operates Chainsaw Creations in Crescent, according to a Website devoted to his work, including various carvings and cabins.

Back in 1995, the Bureau of Land Management told Medenbach he had to leave his makeshift cabin on federal land in northern Klamath County that he claimed to own.

"I feel the Lord's telling me to possess the land, and I can legally do it, because the U.S. Constitution says the government does not own the land," said Medenbach, who described himself as a born-again Christian, according to an Associated Press story.

He also was arrested in 1996 after refusing to answer charges of illegally occupying a campsite on Washington's Gfford Pinchot National Forest for more than three weeks, The AP reported. Medenbach claimed the printing of his name in all capital letters in court documents rendered the documents invalid, an argument often raised by those who call themselves "sovereign citizens."

A 2002 book by Robert L. Snow called "Terrorists Among Us: The Militia Threat," also included Medenbach, referring to him as "a member of the Oregon Militia" who had a number of confrontations with county officials regarding building codes on his five-acre property near La Pine. The book said Medenbach was building his dream home out of discarded refrigerators, water heaters and other such material.

"A 'code' is only a suggestion. It's not a law," he was quoted as saying, adding, "He subscribes to the legal theory that the courts have no authority over him because all judges belong to the state bar association, which he believes is unconstitutional."

"I'm willing to pay the price for my convictions," said Medenbach. "Someday, when the laws become too stringent, people will start waking up."

Ammon Bundy would not comment about the arrest, but the group was busy in other ways Friday, taking down at least five "surveillance" cameras they claim were being used by the FBI or others to spy on them.

The group said Harney County residents alerted them to the cameras, about 15 miles from the refuge, which they claim were being used to monitor their comings and goings.

"We don't like being spied on," Randy Bundy said.

Also Oregon Public Broadcasting's Amanda Peacher tweeted a photo Thursday evening of a road freshly cut by the militia on the refuge, prompting a stern statement Friday from the U.S. Fish and Wildlife Service.

"Building new roads without appropriate planning makes important cultural artifacts vulnerable to desecration and disrespect. It also puts habitat and wildlife at risk. Not to mention the unknown cost to the American taxpayer to repair the damage caused by building unplanned roads on the Refuge.

"The Service strongly condemns any action that puts cultural resources at risk. We take our trust responsibility to our First People's very seriously, and this is disappointing," the agency said.

FWS spokesman Jason Holm said of the action "It's deplorable. I'm not sure what part of the occupiers' interpretation of the Constitution promotes the destruction and desecration of culturally significant Native American sites. We share in the outrage of the Burns Paiute Tribe. This is disgusting, ghoulish behavior."

A community forum that was planned Friday night in Burns was canceled after county officials denied them permission to hold it at the county-owned fairgrounds.

Travis Williams of the Harney County Safety Committee announced the cancellation Friday morning: "There is no meeting tonight."

A spokesman for the group, Arizona rancher Robert "LaVoy" Finicum, said they are hoping to reset the meeting for Monday, if they can find a place to hold it.