Jill,
My only experience is with someone operating a daycare facility.
Since our playgrounds were not considered public we were also concerned about liability. Therefore, we consulted our attorney.
On the advice of our lawyer we required the member and every parent to sign paperwork (which the lawyer drew up) - and I'm pulling all of this from memory - specifying that the common areas were not public property and therefore did not need to comply with various regulations that would be required of public property and that the guests understand this and agree to hold the Association harmless for any injury that may be attributable as being preventable by such regulations.
Basically the daycare was no longer an issue as the member didn't want to be held personally responsible and the parents didn't want to sign the papers.
You may want to check with your Association's attorney for something similar.
I know that
VA statutes do provide some protection for individuals and corporations that have equine activities.