premise: The National Park Trust identified 20 high-priority sites - including the Blue Ridge Parkway in North Carolina and Virginia and Everglades National Park in Florida - as areas with private property that could be sold.
hypothesis: There are areas with property that could be sold in many states
reason: There were at least 20 states, because the 20 is only considered high priority, there are probably more, which means the word "many" is probably applicable