An esker left by retreating glaciers cut off drainage to the north (the river Brosna catchment).

Although usually classed as a relatively intact bog, it has been negatively affected by peat extraction and by the construction of the Clara to Rahan road in the late 18th century.

In the early 1980s, Clara Bog East was drained for potential industrial peat extraction, but public requests were made to the Irish Government to preserve the area by a number of international naturalists, David Bellamy among them.

In 1987, both the Dutch and Irish Governments signed a technical agreement for co-operation in the area of peatland management and restoration.

[6][7] For centuries the Irish have taken turf (peat) from bogs as fuel for their fires, and there has been resistance to the requirements of the Habitats Directive for a ban on the tradition in protected areas.