If you already have insurance on a car or truck, check with your insurance company. I got a second policy on mine for my ds even though my insurance company doesn't really advertise that they insure quads, bikes, boats, etc. like some do. And since I have multiple policies with the truck and quad there is another discount for that, so my ds is fully insured for only $82 a year.
I don't think State Farm covers medical for the rider when insuring ATV's. The medical is for the other person if you hit someone. I have heard that for off road riding, you are going to get hurt. It is just a matter of time.