The Portland Tribune reported Monday the heads were visible to passersby last week.
Warren resident Cici Lires wrote in an email to the South County Spotlight she hadn't seen anything like it in the past eight years. "Why out towards the road, facing the road where wild animals can get to them, Where everyone can see them?" she asked.
Another Warren resident who asked not to be identified saw the heads while jogging by.
"I thought, 'holy cow that is the most disgusting thing,'" the runner said. "And they stink now."
The cow heads belong to Port of St. Helens Commissioner Colleen DeShazer, who told the Spotlight they were being dried out so they could be sold.
"Those are my cows. We legally butchered them," she said. "We save the heads, we dry them out, we sell them."
"If you don't like it, don't live in the [expletive] country next to a farm."
Columbia County Sheriff Jeff Dickerson said the grisly display isn't against the law.
"It's not illegal to have a cow head on your property," he said. "There's no state law or county ordinance to prohibit that."
Charlize Theron not engaged to Sean Penn 'yet'
Pistorius testifies he didn't consciously pull trigger when he shot girlfriend