Matt and I went with our friend, Angie, to Hawk Mountain Sanctuary a few weeks ago. It is located in Hamburg, PA, north east of Harrisburg. If you have never been there and find yourself in the area, go. It is so worth it, if only for the views:
Hawk Mountain is a valley in the eastern PA mountains where, by some strange happenstance, a vast majority of migrating raptors from the entire east coast pass through. Eagles, Osprey, hawks of all kinds, kestrels. Just a few days before we were there, a whopping 1600+ Broad-winged hawks came through. In one day!
We had beautiful weather, clear and not too warm. We could see 35 miles that day. Unfortunately, the winds weren't doing much which meant the hawks weren't, either. That is one of the problems with planning a trip ahead of time, you never know what you're going to get.
We did see several hawks up close, two Osprey flying above us. A few Bald Eagles waaay far off. Three sharp-shinned hawks having a serious argument right above us. Several piliated woodpeckers.
One year, Matt and I had a great time watching the hummingbird migration. Seriously. You could just barely make them out above the treetops, then all of a sudden you had, say, 8 tiny green missiles whiz past your head.
Their website is extensive, they've been keeping migration records for 75 years. If you plan to go, you can check out and see when various birds are most likely to be migrating. They have 'migration forecasts' on their website, too, based on weather. They also have an email update weekly, which is great fun to read.
The trails at hawk mountain are pack in/pack out. No trash receptacles. Scant restrooms. They also have extensive hiking trails for just hiking. Just watch out for bears and snakes.