It seems very summer striped bass are caught up the Delaware River, way up the Delaware River. So if Delaware Bay is mile marker 0, and Trenton is 130, just below Cannonsville Reservoir on the West Branch is mile marker 330. One place that always seems to attract stripers is Junction Pool, aka Bard Parker, which is where the East and West Branches meet in Hancock, New York.
I've never caught one that far up the Delaware, but did try one time when I was guiding, after a trip of course. Stripers love trout. Either liveliness in deep lakes or rivers, but they'll blow up on a hooked trout like a shark does on a striped bass.
And it looked like this isn't a hybrid, but a striped bass from the ocean, that wanted to enjoy the cooler water temps, 70-74 that the junction pool brings this time of year. That's Joe D from Cross Current Guide Service with that nice bass.