A pity we don't have a system as in New Zealand, as far as I can gather their ACC(accident compensation corporation) covers everyone for everything, there is no need for any liability insurance.
http://www.acc.co.nz/making-a-claim/...ered/index.htm
For instance, there is no need for car insurance, this is financed by a levy on fuel and car tax.
So, organising a fell race doesn't need insurance or any worry about claims, automatically covered. This is how I understand it, interesting concept, but put a vast numbers of lawyers out of work!!