Hiking in the South Mountain Preserve near Allentown, starting from the Emmaus (other) side of the hill we can see from our sunroom. We got almost to the high point but decided not to go on the Yellow trail near the ridge which would have taken us close (next time?). Crossed Trout Run and Rodale Run, two streams/rocky reentrants, which could be impressive after a good rainfall.
Trail map (Lehigh County has a wonderful site for trail maps...very easy to use with excellent topo maps)
Wildlands Conservancy trail map (this is the one we had with us that doesn't have all the trials of the first link)
Lots of folks in the park today. Some nicer woods higher up the side of the ridge (mostly a variety of oak and oak saplings below, some beech mixed in higher up, plus some large tulip poplars in the uplands).