My recent experience with cable in campgrounds indicates that more and more are upgrading to digital. Because you normally use a cable box to view these channels, many are lead to believe that they are "encrypted".
I have found that not to be true. The channels are actually there, and viewable, but they don't appear on the guide channel. For example, if you normally tune channel 7 to see digital channel 7 on the cable box, you may be able to see that programming on channel 502.4 or something like that using your generic ATSC tuner.