It's not on that list, and the reason why was kicked around here ad nauseum back when this first became news. Once again you bring a matter that has already been settled to the board and think you're the first hot shot to find it. If you do your DD correctly, you'll find your answers...and I'll give you a hint....MT didn't lie. Nyquist gave you a good starter.
The privately-owned Corobici Wildlife Refuge would not appear on a list of national parks that are managed by the Costa Rican Ministry of Environment and Energy (MINAE).
A national park is "a tract of land declared public property by a national government with a view to its preservation and development for purposes of recreation and culture." (See: http://www.answers.com/topic/national-park ).
"Private property is sometimes used synonymously with individual ownership, but the term may also be used to include collectively-owned property in the form of corporate ownership. Both of these are distinct from public property, which is that which belongs to a whole community collectively or a state." (See: http://www.answers.com/private%20property ).