Residents in Desert Hot Springs, California, say a man is stacking piles of rocks on medians and sidewalks along Palm Drive near Pierson Boulevard. "He stacks them pretty good," resident Jesse Rodriguez said.
"He does them every day and wherever he's at."
Local businessman Brandon Trujillo said: "It's random. It's odd. I'm not sure why he's are doing it or what their benefit from it is."
The problem is the rocks tip over and fall onto the road.
One woman has warned drivers to be careful. She couldn't see the rocks on the road, ran over some and had to pay $200 for a new tyre.
"It could create some blow outs and could cause accidents from that.
"I know it's not the best place to be doing that," Trujillo added.
Desert Hot Springs city leaders said they're aware of the rock piles and want it to stop.
Police say it's not illegal, but the man could get in trouble if someone gets seriously hurt.
With news video.