At the Wahweap Marina. Drive down the right side of the Wahweap launch ramp and about a 1/3 of the way down turn right down to the parking lot. From there walk down towards the Marina store you can't miss it. Good luck and have fun.
Thanks for the info Steve. I attached a Google Street View picture of what I am guessing is the fishing dock based on your directions. That looks like it would be perfect for getting the line wet. That is awesome that you caught 18 stripers. Nice work.