I'm a life long trout fisherman also but when you can catch 40 stripers in and hour or 2 it makes you wonder. Don't know if you have a boat but if you do go to the dam and fish on the chain barrier with half a chovie on a 1/8 oz lead head jig. Cast it out as far as you can on 8 LB line and just let it sink on its own. Cut 4 or 5 chovies in 3s and toss out around the boat. If they are there they will take the bait on the fall. If it gets to be straight down, wind in and recast. I've caught hundreds with this method. I've actually found that the east side of the chains does better for me right near the wall. If I find nothing biting in half an hour they just aren't there. Read the reports here to find where to go next.
There have also been lots of stripers caught at the walk in area on the east side of the dam if you have to fish from shore. Even the fishing dock at Wahweap Marina produces at times.
BTW, you know the river below the dam is loaded with rainbow trout, right?