Because many peat deposits occurred in shallow basins on prime agricultural land, most have been drained. A recent search of county soil maps and high-altitude air photos revealed that all peat deposits listed by Survey geologist S.W. Beyer in 1908, representing over 15,000 acres, have been drained and are under agricultural production. Only those in public marshes or those less suitable for farming remain today. In recent years, emphasis has shifted from utilization of peat to its conservation, with more attention being given to the state's smaller deposits. Many of these sites, called fens, occur on hillslopes and are associated with springs or seeps.
Drainage is impractical because of the continual flow of groundwater supplying the fens.
Often only one or two acres in extent, these unusual hydrologic sites harbor many rare plants, and recognition of their biological value and the need for their preservation is growing.