My boss lives in a water-ski enthusiasts' housing development built around a lake. All the people that live there have boats and actively enjoy water-skiing. They pay an annual premium to maintain the lake and docks, etc. He can go home, and 10 minutes later, be wake boarding on the private lake.
Why not an off-road enthusiasts community? Because most of us are too broke and disorganized to pull it off?
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I'm not sure liability is even an issue--the home owners probably have to sign away any rights to hold anyone liable for injury. Water skiing is dangerous, and it works for those communities.