Murder Hole Cave Facebook page https://www.facebook.com/Murder-Hole-Cave-243677605990620/?fref=ts
Movie was produced by Hodag Video Productions http://www.hodagvideo.com
National Speleological Society http://www.caves.org
Blue Ridge Grotto in Roanoke, VA http://www.blueridgegrotto.org
West Virginia Cave Conservancy (WVCC) http://www.wvcc.net