The dams along the Skagit River coming down from the Cascades are all pretty interesting but Diablo Dam is the easiest one to access so, when mum was visiting, we made the side trip to go across it.  I actually missed the turning for it when we were heading into the mountains but I made sure to remember where it was when we headed back down.  Driving across the top of the dam is pretty cool but it is a little narrow if you meet traffic coming the other way.  There was a good flow of water coming through one of the spillways while we were there and that looks impressive compared to when everything is calm.