Hidden beneath the woods off of Tweed Boulevard near Nyack, New York are the Clausland Mountain Tunnels, a series of cement halls that were put in place to keep World War I soldiers safe, but are now simply the home of graffiti artists and legends of satanic ritual.
The tunnels were originally part of the Bluefields Rifle Range which was meant to be used as a training ground for members of the New York National Guard. The tunnels were built to allow soldiers to pass under and around the open fire ranges without the risk of being hit by a stray bullet. However, the site was seen as an expensive boondoggle from the get go. National Guard officers, for whom it was being built, called it “one of the most costly blunders in the history of the state”, and locals complained that stray bullets were falling from the sky and putting holes in their barns. Built in 1910, it was only in use for a scant three years before the base was closed.
After the closure of the base, the tunnels were left intact. The tunnels quickly became home to numerous urban legends and underage drinking. It’s rumored that there are miles of tunnels that litter the subterranean landscape of the area, but there seems to be considerably less than that. What tunnels do remain are strewn with garbage and covered in graffiti. The legends surrounding the tunnels range from those involving satanic ritual to bodies being dumped there by the mob, to suicides and murder though little evidence of any of that exists. One of the tunnels is accessed by crawling under the roots of an old tree, like something if out of a fantasy novel.
There are a few entrances to the tunnels, and at least one of the tunnels has collapsed and is impassible, so their safety is somewhat suspect. The tunnels are home to a number of large insects including wolf spiders (which look scary but are basically harmless) and cave crickets (also harmless) which grow to the size of a tennis ball and leap off the walls when startled by a passerby. Nonetheless, despite all the reasons not to go exploring in a collapsing tunnel filled with thousands of fist sized crickets, people continue to visit the tunnels, looking to find a little adventure.
Know Before You Go
There is an entrance to the Long Trail in a nearby development; the tunnels are about a 1/4 in from the entrance to the trail. You can enter between #4 and #6 1st Class Marsico (yes, that is the name of the street). It's pretty new so may not be in gps. Search for Valenza Lane in Blauvelt. You can also enter by hiking through Tackamac North Park out across Marsico Ct. The GPS marker is set for the entrance under the tree roots.