My son & his family lived in Boise, now in McCall. I see them twice a year, always take a rod.
Boise R through town is just OK, mostly stocked and heavily fished.
Idaho is a huge state and folks there think nothing of driving 2 or 3 hours to fish. S F of the Boise is 1.25 hours east of town, great tailwater. Silver Creek is 3 hour east of town - legendary spring creek.
Ohwayee in OR is 1.5 hours west of town, great tailwater.
For fly fishing, McCall is mostly small high alpine lakes. Payette R south of town is marginal. Other good rivers east of town look close but mostly dirt roads at 30 mph so 2+ hours.