I got a call today from one of my customers. He says there is stain on his bluestone that came from my tires and he can't get it off. "He will talk to me next week and I should be more careful" Where the stone is I have already mowed about a third of the lawn before I get to the stone. I remember seeing something on the stone but didn't [ay attention to it because we have gotten a lot of rain lately and just thought it was wet because it was right where I would have it hit it first. I go over this every week. never left any stain before. I think there there had to be something in the lawn. Sorry, it's just been one of those days.