Blauvelt State Park is surrounded by mysteries and legends. Horrible crimes have occurred here, and legends of evil cults and supernatural events have been told for decades. At the center of the park are a series of tunnels, which locals call the Tweed Tunnels, and Clausland Mountain Tunnels.
The tunnels and surrounding structures were originally built in 1910 as Blauvelt Rifle Range. By 1913 the range shut down due to complaints from surrounding communities.
Ownership was transferred to the Palisades Interstate Park Commission and the the park was renamed Camp Bluefields. It was run by the YWCA as a camp for young women from New York City until 1918.
During WWI and WWII the range was used for military training. after the second world war it was abandoned.

Over the years, the buildings and structures were left to decay, and have been covered in graffiti. By the 1970s and 1980s evidence of several crimes had been discovered in the park and surrounding woods, including the aftermath of 2 serial killers.

Around that same time legends of demonic cults using the Park began to spring up. there are also reports of a mysterious vortex, and an apparition in one of the buildings.