Calcareous shoreline outcrops are close enough to the waters of the lakes and streams they surround to experience significant amounts of wave and ice scouring, which distinguishes them from shale cliff and talus communities that occur on vertical exposures at slightly higher elevations.

Cobble shores also occur along the shores of lakes and streams, can also experience a significant amount of scouring, and can have vegetation that is very similar to calcareous shoreline outcrops (particularly in the calcareous regions of the state). Cobble shores are distinguished from calcareous shoreline outcrops by their very round rocks that have been well weathered by water action. The cobbles can be loose or embedded in sand, gravel, or peat, usually with vegetation rooted between them. Calcareous shoreline outcrops have large slabs of limestone, angular rocks, and exposed pavement bedrock.