Sand and Gravel deposits
The glacial legacy of the Cold River is most evident in the sand and gravel deposits scattered through the Corridor. These deposits are economically important for the region, allowing it to be self-sufficient for aggregate needed for construction, road building and winter road maintenance. Soil types classified as having some potential as sand and/or gravel resources encompass much of the corridor. The NRCS rates soils as being either "probable" or "improbable" as commercially useful sources of sand and gravel with a minimum of processing, basing these ratings on grain sizes, the thickness of the deposit, and the content of rock fragments. The criteria used are a deposit at least 3 feet thick and less than 50%, by weight, large stones. In reality, not all of these deposits would meet the stricter criteria of sand and gravel excavators looking for economically viable sites where the investment needed for site development and permitting must be weighed against the volume of good material at the site. Access is obviously another determining factor of economic viability. One large active sand and gravel operation, known as Cold River Materials, a Division of Lane Construction Company (formerly Whitcomb), is located in the corridor in Walpole and extends across the River into Langdon utilizing the vast amounts of sand and gravel left in the lower Cold River valley by glacial melt waters. Several other smaller active and abandoned excavations are located within the corridor in these soils as well.