Just got back from ID last Tuesday.  Boise is a wonderful town.  For good info:  Riverkeeper on Broadway.  And, yes, Cabela's is there (if you have any money left after you depart NV).
Barber Park is nice if you're fishing in town.  We fished the S Fork Boise 5 miles downstream from Anderson Dam for a few days.  Low water (no floating).  Fishing fair.  Weather tough (rain, wind). bwo's.  
IF YOU CAN:  Silver Creek (5 miles E of 20/93 junction).  Owned by the Nature Conservancy.  Bring a float tube.  You can camp at the fish hatchery for nothing.
The Big Wood (Ketchum) had some good bwo hatches 1-4 pm.
We did 5 days floating the Owyhee at the end of July.  pmd hatch extraordinaire. SMALLEST fish:  16 inches.  However, the browns do not do aerobatics like rainbows.  They will put a hell of a bend in your rod, though. 
 
  
 