This page has reservoir and river levels on it. Right now, GP is at 944, full pool is 1010, so its about 66 feet from the top. I've done very well trolling shallow in May, but the fish have been very scattered in that month. I think they bite all year long, but they don't really start to school up and get agressive until June. In May, they're agressive, but you have to find them, and then find them again, and again, and again.
happybrew