Rare photo showing the original entrance to Spring Valley Caverns (looking down into collapsed sink).

Photo by Tom Bayer, former geology professor at the University of Winona

May 1967.   Historic photo showing the original natural entrance to Spring Valley Caverns.  Notice the concrete blocks to the right which were later used in a failed commercialization attempt.

After the concrete blocks were used to create the stairway walls into the cave, this WWII Quonset building was placed over the entrance.  This structure served its purpose well until 1998, when it was replaced by the new building.

Today, the main entrance into Spring Valley Caverns is this newly constructed 3 level, 22 x 40 x 38 foot tall structure.