Okay, I was thinking lower dam is the one near Nampa but I was wrong. At the Upper dam. Anyways, where I was at is the park that is nearest to Nampa and the gate is open to where the concrete boat ramp is and near where the USFWS buildings are. So, Upper, Lower or whatever, I was near the park headquarters, but on the East side of that dam near the concrete outlet structures. Sorry for confusion. I'll see if I can fix the posting.
Hope that helps.
Bob