The Shuswap area can offer some great fly fishing, especially the Adams River. The Adams River is famous for it's huge sockeye salmon run, in late summer /early fall the sockeye retuirn to spawn in the millions. The big rainbows come out of the lake to feed on eggs. Best patterns are egg and flesh fly's. Try doing a search for Adams River Fly fishing, you should find some info on that river.
Here is asome good reading on Adams river
Sockeye Salmon, Adams River, British Columbia. Adams River Salmon Run, BC