They used to have a bachelor party poker run every May here. I don't know if they had an insurance policy, but they did have everyone sign waivers.
Typical attendance was 100-120 bikes, which is huge for Helena. One year they decided to arrange a police escort out of town. Yeah, that lasted five seconds. 90% of the riders scattered and went their own ways. This was before I had my bike and I was driving the chase truck.
