That is good advice, but only works for national parks, and the closest one is 100s of miles away. There are not that many national parks east of the Mississippi. There are some, but its not like out west where it seems you throw a rock and it probably lands on a national park.

On the other hand the city I live in has three separate rails-to-trails conversions within 2 miles of my house and a riverwalk. Every little county park seems to pride itself on having elaborate marked hiking trails. In a land with lots of rivers every "three taverns and a gas station" village hovel seems to have some kind of riverwalk, aside from the big one in my hometown. Just one of the state-level parks in my county has 29 miles of hiking trails. I wasn't kidding about just my little county (well, little county as in half the surface area of Rhode Island) having 100s of miles of hiking trails.

I would like to hike a national park someday, but its so much easier (and cheaper!) to visit a local trail.