Cliffs are great vantage points to look for weed beds, drop-offs, channels, and shoals. Cliffs afford shade, more favorable water temperatures, and collect flotsam which includes drowned or struggling aquatic and terrestrial insects. Some cliffs furnish seepage of spring water which enhances the favorable water temperatures.
Fish occasionally mill about cliff areas, focusing their attention to the surface. Windswept insects may hit the cliff and end up in the water. An errant breeze may blow a terrestrial off a ledge into the water. Commonly, food sources come from the surface in cliff areas so similarly they can be fertile places to fish dry flies.
Cliffs need not be high to be productive. Snowbanks can serve as temporary cliff-like areas. Rocky shorelines are common in both reservoirs and in some natural lakes. These shoreline areas fish well with terrestrials. Drift lines of windblown objects commonly gather at cliffs and rocks. These rocky shorelines are similar to cliffs. An earth-filled dam provides an ideal rocky shoreline. It is adjacent to a steep drop-off. These drift lines harbor many dead adult and stillborn insects.