Yes I'm familiar with Hatfield. Dated a gal from Horsham. Not too familiar with the streams in that area, but PA is filled with thousands of creeks and streams so I'm sure there is plenty of places for you to explore.
In my previous post I mentioned guide books. I did a quick Amazon search for the one I remembered and got the some good results. Just follow this link Amazon.com: trout streams of Pensylvania: Books
The first book I remember as being very good and detailed by sections of the state. It is called "Trout Streams of Pensylvania"