This is complicated, and the boundaries are a little unclear. If the club, or a member, needs a liquor license to serve liquor, coverage is in doubt. Given the complexity of the liquor liability rules under the policy, extreme caution is needed when a club mixes liquor and orienteering. You should read the policy before you do it, and not rely on this summary. The policy excludes, among other things, unusual events such as fireworks, swimming pools, rock concerts, carnival and amusement rides and camps or campgrounds.
Coverage applies without notice to the insurer.
That is true for land owners, as well, although many of them require a certificate of insurance specifically naming them. The premium is based on club membership, which the USOF Office supplies to the insurer annually. Some people have suggested that the basis for charging clubs should be something else, such as the number of events or attendance at events. But the insurer determines risk, and therefore premiums, on the basis of membership, and USOF follows suit. Bet remember, this is a liability policy, and the question of whether a club or club member is liable is not a USOF insurance question, but a state law question.