Decorah Edge
The “Decorah Edge” is defined as the area in which the Decorah, Platteville, or Glenwood formation is the first encountered bedrock according to the “Bedrock Geology: Steele, Dodge, Olmsted and Winona Counties” data plate produced by the Minnesota Geological Survey – University of Minnesota in 2004, as modified by field investigation or more precise mapping; and having a depth to bedrock of less than twenty-five feet according to the “Depth to Bedrock: Steele, Dodge, Olmsted and Winona Counties” data plate produced by the Minnesota Geological Survey – University of Minnesota in 2004, as modified by field investigation, reliable well logs, or more precise mapping; and for which there are contiguous adjacent areas with the Cummingsville or higher formations as the first encountered bedrock.