I have to disagree with Bob Cahill (Oct. 21) when he says concerns over all-terrain vehicle use are overstated. My granddaughter and her parents incurred $400,000 in medical and doctor bills for a broken back due to an ATV accident. The owner of the ATV, who also owned the property, had no insurance. I don’t believe they are self-policing. They may be respectable, but not responsible. If you want to see the damage ATVs can do, check out the Columbia Basin sand dunes area. Go there on Memorial Day when there are thousands of ATVers in the dunes. Over the last 30 years, the dunes have disappeared.