In the survivalist subculture or movement, a retreat is a place of refuge. Sometimes their retreats are called a bug-out location (BOL), a bunker, or a bolt hole. Survivalist retreats are intended to be self-sufficient and easily defended. Generally, they are located in sparsely populated rural areas. History While fallout shelters have been advocated since the 1950s, dedicated self-sufficient survivalist retreats have been advocated only since the mid-1970s. The survival retreat concept has been touted by a number of influential survivalist writers including Ragnar Benson, Barton Biggs, Bruce D. Clayton, Jeff Cooper, Cresson Kearny, James Wesley Rawles, Howard Ruff, Kurt Saxon, Joel Skousen, Don Stephens, Mel Tappan, and Nancy Tappan. Survivalists or "preppers" build these survivalist retreats to help them survive in the event of a disaster or simply "disappear," hence, the need for self-sufficiency. 1960s With the increasing inflation of the 1960s, the impending U.S. monetary devaluation, the continuing concern with possible nuclear exchanges between the USA and the Soviet Union, and the increasing vulnerability of urban centers to supply shortages and other systems failures, a number of primarily conservative and libertarian thinkers began suggesting that individual preparations would be wise. This was further reinforced by the effort on the part of the U.S. government to encourage the installation of bomb and fallout shelters in the United States after the Cuban Missile Crisis. Harry Browne also began offering seminars in 1967 on how to survive a monetary collapse. He worked with Don Stephens, an architect, survival bookseller, and author, who provided input on how to build and equip a remote survival retreat. He provided a copy of his original Retreater's Bibliography (1967) for each seminar participant. Articles on the subject appeared in such small-distribution libertarian publications as The Innovator and Atlantis Quarterly. It was also from this period that Robert D. Kephart began publishing Inflation Survival Letter (later renamed Personal Finance). The newsletter included a continuing section on personal preparedness by Stephens for several years. It promoted expensive seminars around the USA on the same cautionary topics. Stephens participated, along with James McKeever and other defensive investing, hard currency advocates. 1970s In 1975, Kurt Saxon began publishing a newsletter called The Survivor, which advocated moving to lightly populated regions to "lie low" during a socio-economic collapse, and setting up fortified enclaves for defense against what he termed "killer caravans" of looters from urban areas. In 1976, Don Stephens popularized