Re: Yosemite National Park fly fishing
Keep in mind a couple of things: Yosemite is one of those "there's no fast way to get there from here" places - and there will be a ton of people in the Valley in July. Totally worth it, though, for the photography. If it were me, I'd go early and/or late in the day for the photography, before and after the crowds.
Back country is good for small, pretty trout. And I agree with K9mark about a ferry trip across Saddlebag Lake to the Carson-Iceberg Wilderness. Good fishing, good photo ops, and a lot less people.
And I wouldn't worry too much about the bears. Sometimes folks get Yosemite confused with Yellowstone. If you do camp out, you will need a bear cannister for your food. But it's not so much the bears are dangerous (although obviously any bear can be dangerous in a given situation), it's more that they've been "humanized" and are extremely clever about stealiing food.