What a beautiful American made icon! It is truly Sad such security is required But my family and I appreciate the reassurance that there is security ensuring everyone's safety!
It definitely is hot there so it is extremely important that you bring water or gatorade to keep hydrated! If you forget more worries there is a cafe available.
There is 10$ parking fee at the parking lot near the cafe/gift shop but if you proceed past the dam there are several spots one can park without paying anything! To get a true appreciation of the dam prepare yourselves to walk it. This is never a disappointment! You can no longer proceed on the original road when attempting to exit. You will have to make your way back into the entrance to leave as well.
This is a worth while site to see especially since there isn't an entrance fee to see this beauty!