Kenneth Medenbach, was taken into custody Friday after police said he drove a stolen federal vehicle from the wildlife refuge to grocery store about 30 miles away in Burns.
“Sometimes we make dumb choices, don’t we,” said LaVoy Finicum, who frequently serves as a spokesman for the occupation.
It was the first arrest made by police in connection with the armed occupation at the refuge.
Medenbach is being held at the Multnomah County Detention Center in Portland.
An official at the Harney County Joint Information Center said authorities are working to hold Medenbach accountable, but an initial court appearance has not been set.
Finicum said Medenbach has been a “backbone” and major supporter to the armed protesters at the Refuge.
“To take a truck and drive it in, that is not registered and licensed yet to Harney County, which we hope will soon be, could’ve been a better choice,” Finicum said. “We’re going to really miss him.”
Medenbach is prohibited from being on federal land as a condition of his pretrial release from a previous charge.
OPB’s Amelia Templeton contributed to this report.