At a normal stage of water a bass will often lie on the down stream side of a boulder in quick water where the current has scooped out a hole in the bed of a stream and here you will often " connect " with a big one. This hole usually shows as a big, dark patch on the stream bed and it is good strategy to first cast up to its edges before floating a fly directly through it.
In the average river most bass will be taken near the shore line. Overhanging banks, trees or bushes that lean over and admire themselves in the reflection of the surface; docks, piers, fallen trees, partially or totally submerged stumps (river men call 'em "dead heads") wing dams, boulders, brush heaps — anything