Apparently the locals have spent 12 hours underground & not found the end:
http://www.channel4.com/programmes/walking-the-americas/on-demand/64332-004
Mike
http://www.channel4.com/programmes/walking-the-americas/on-demand/64332-004
Mike

Including: Into the Echo Chamber, Tim Allen reports on another magnificent Yorkshire Dales find by the Space Miners....and: The Great Geoff Yeadon, undoubtedly one of the greats of the caving world. Following his death at the age of 75, Geoff Crossley, Martin Grass and Mick Nunwick pay tribute to him.