In Southeast Houghton there was a large amount of glacial outwash deposits which may have been distributed by an outlet channel for Lake Duluth which flowed southward toward where the present Pilgrim River now flows.  Driven by the enormous flows from melting continental ice sheets which were miles thick, these gravel and boulder-rich deposits produced huge volumes of sand and gravel.  When development of the commercial businesses occurred in East Houghton, the sand and gravel deposits were leveled and used for building. The large boulders were piled together in a group along one side of the excavated area, where we find them today.  Note the great variety of rocks and the smoothed surface of these great boulders.  All of the local rocks are found here, and many rock types from hundreds or even thousands of miles away, brought here by the glaciers.