Whiting,
Regardless of which ramp you use you can troll in open water directly in front of the cement ramp right across the dam. I caught my fish in 58ft of water and the other two hits were in similar depths but I also saw arching on the sounder out in the 100ft of water. The depth of the lure will be dependant on whether you can make out fish on your sounder and what depth they are at.
Hope this helps
Darryl L