I am very happy that we have land protected from development, as long as people aren't locked out. I've encountered several categories of conservation areas:

• National/federal lands
• State/Province lands
• Local lands, usually parks
• Semi-Private land conservation organizations
• Private land conservation organizations

These each have advantages and disadvantages. Here's my thoughts and grievances:

• National/federal lands
  I don't have much experience with national parks other than Valley Forge National Park (formerly a state park).
  • Expansive
  • Rules that aren't particullary tuned to local environments
  • Land managers might be constrained by bureaucracy
  • Tourists can totally overwhelm some areas
  So for years Valley Forge Park allowed orienteering events. I participated in just the last few before permission was withdrawn. It's a shame - it has some nice woods and is in a central location. Valley Forge Park promotes itself as a historical location, and it is, but the overwhelming majority of its visitors use it for recreation rather than visiting its authentic and re-created historical artifacts.
• State/Province lands
  I've had mixed results with state parks. Some managers historically made it difficult to hold events there. Other parks like French Creek State Park seem wide open to having events there, including orienteering events where runners go ever which way through the woods.
• Local lands, usually parks
  Lorimer Park in Abington Township is a county park where the rangers have a great attitude. It's refreshing and it's a great park.
• Semi-Private land conservation organizations
  Maybe this is the sweet spot. The best case scenario is that there is some public money available but the area can be run locally. The fact that there is public money involved means that the area will generally be open to the public. The private part keeps the area responsive to its members/donors who are hopefully also its users. The McKaig Nature Center is a good example of how this can work.
• Private land conservation organizations
  Private places can set their own rules, especially access times, authorized trails, etc. I admire any place that is totally privately funded but still allows the public access.

My final thought on nature preserves is that they frequently have pro "Climate Change" agenda or programs. I'm not really a fan of that and don't really know what a land manager could do about climate change anyway.