Generally, afternoon fishing is better than morning for both striped and black bass. That is a result of overnight cooling and afternoon warming. Bass prefer 60 degree water and are more aggressive at 65 than 58.
Specifically, both largemouth and smallmouth bass are spawning and guarding nests. Reports from Bullfrog and Hite indicate that bass fishing is good all day long (even mornings) on tube jigs, soft plastic grubs, crank baits and just about everything else, even top water. It appears that fishing is as good as it is going to get right now. If you don't catch bass then try different spots and different lures. You should be able to find bass and then exploit the pattern once it is discovered. Bass will spend some time each day on spawning flats. Then they will move to the breaking edge of rocky substrate, poised between deep and shallow water. Then they will go deep and finally come back shallow. Fish right on the break line and cast to deep water and shallow to find where bass are currently located. You should catch fish. If you don't try using 4-6 pound test line to entice shy bass in clear water.
At Wahweap there is a flurry of bass activity early in the morning. Morning to mid day is slower but it gets really good in the afternoon and evening. Use the same bass techniques mentioned above. Catch a fish, diagnose the pattern and then go get some more bass.
Striped bass are running along the canyon walls at Wahweap. They move from the dam to the upper end of Navajo Canyon and back They will stop and rest along the way and can be found anywhere in the narrow channel. The power plant intake and dam are going to be good some time during the day. But if that isn't happening when you are there, then try upstream or down to find the present location of the school. You may try 5 spots with no luck and then find more fish than you can imagine at the sixth spot. Use anchovies at 40 feet to start and then move the bait up or down depending on what the fish want.
In the upper lake trolling seems more effective for stripers than fishing anchovies. The pattern works the same way. Troll likely looking spots in the main channel or back of the canyon. When a fish is caught turn around and go back over the spot. Catch another and then keep trolling or try anchovies when the school is pinpointed. Use rapalas, shad raps, little macs, and other long thin minnow shaped lures that run 15-20 feet deep. Shallow runners (rattletraps and short lipped crank baits) can be used in the backs of canyons where depth is less than 25 feet and water is murky. Stripers are active and moving. It can be difficult to catch a moving target so cover a lot of water to find stripers.
Walleye are hitting now in the very early morning in the shade of steep cliffs and on rapidly descending rock slides and shelves. Fish walleye early and then look for bass and stripers.