I used to live in Henderson and would fish the Boulder basin from shore regularly. I also worked the fishing dept. at the Sports Authority, so I had a fairly steady supply of info.
In the Boulder basin area, the place I did best was in the area of the Hemingway Cut, which is N of the Hemingway Ramp about 200 yrds. At this time of course with the summer heat it may not be very good here. If you go there and see shad the Stripers are there, if no shad, then no Stripers. BTW you can Cast net the shad for live bait. They also stock trout here sometimes, and if there are trout around large stripers will be nearby. If you can find a Castaic 8" Rainbow Trout Swimbait at you local Walmart try fishing them in that area. (They didn't have these back then, but I've used them elsewhere and they're good).
Other good areas are out at the very end of the levee that closes in the Boulder Marina. This can be a good area to throw Pencil Poppers(quartering into the wind), or try a weightless anchovie or live shad with a 1" diameter casting bubble filled with water.
If you have a boat I'd troll deep or vertical jig over any Shad balls I could find with sonar. When I was there the main body of the Striper population stayed 45-80' deep all summer. The Islands almost straight out from Hemingway Launchramp produced some nice stripers that year especially trolling deep with big trout imitating lures.
I hope this helps.

Tight lines,
Wade