History of bluestone quarrying in the Catskills
Bluestone Sidewalks
Old History
upperdelaware
nytimes.com
Kingston link
1930PDV our catskill Mountains
quarriesandbeyond.org
wikipedia.org/wiki/Bluestone
wikisource.org
Dec Link
hudsonvalleyguidebook/bluestone-quarries/
youtube.comBluestone
Opus 40 Link
Storm King
groundsforsculpture
USA Parks Images
decordova Web site
socratessculpturepark Link
Red_Rocks_Amphitheatre
Biophilia_hypothesis