Last week there were 100s literally. Saturday there weren't as many because they had the spill gates going strong and covering all the rocks, so they had to hang elsewhere. Aponi06, as for how long they are there, my 1st time every going to Conowingo Dam was in early March '09 and there were still a few Eagles around, but not like this time of year and December and January. So you have time to go and see them, just make sure the family is well dressed if you go because it's colder near the dam than inland.
I got some fly overs Saturday and the typical Eagles in the trees (4 of them).