Exploring Hailes Cave presented by Thom Engle Of the caves known in Thacher Park, Hailes Cave is the longest.  Historically, the cave was visited frequently, but in recent years it has been inaccessible.  With the new Thacher Master Plan the cave is being remapped by the Northeastern Cave Conservancy, the same group that owns Clarksville Cave.  Take a photographic and cartographic tour of the cave and learn what’s there and what the future of exploration may reveal.