I think you'll have better luck/chance of viewing bald eagles outside of GVRD area: e.g. Vanc Isle, North Shore (along the stretch between North Van and Whistler, Anything east of Mission/Chilliwack, etc.
No such luck in GVRD due to lack of farmland/habitat suitable for bald eagles to hang out.
They are here for the salmon. So you want a place close to the river with salmon for better photo shots.
My friends went to Squamish 2 years ago and got some excellent shots. But they said to prepare yourself for the bed smell of dead salmon all over the place.