In the 1920s, the narrowest place in the Arroyo Seco was dammed to control flooding, and it was named Devil’s Gate Dam, for the demon-like face of a horned figure in the natural rock formation. In the 1940s, a group of occultists became interested in the area and attempted rituals intended to open a portal to Hell. The group included rocket scientist Jack Parsons (a follower of Aleister Crowley’s Thelema) and L. Ron Hubbard (future founder of Scientology). Their goal was to bring forth a “moonchild,” which they hoped would be an Antichrist figure that would lead a Thelemic revolution.