Two weekends back Tammy and I visited Ragged Mountain Natural Area, in Charlottesville, for a small day hike. The trails are essentially around the Charlottesville Reservoir. One thing that was unique about this park was that no pets are allowed, not even leashed dogs. The reason given was that it increased the wildlife viewing enjoyment for all visitors to the park. I can agree with that logic.
[edit: the trails are not really "in and around" the reservoir...they are really just "around" the reservoir :-)]
On the one hand, I can see how a dog owner would find that rule annoying or unfair. On the other hand, I have been at plenty of parks that allowed leashed dogs but saw dog owners that ignored the part about a leash, and let their dog run free. That can be annoying or unfair to people who are in the park and not particularly interested in interacting with the dog, or would rather the dog did not disturb whatever wildlife there was to view.
Like this deer, chilling out in the ferns.