|The following is based on Van Buren and has not been confirmed by canon sources.|
Sleepers are scientists that were in deep sleep before the war began, and students of Presper who did not agree with his methods and were put into a comatose state.
Before the Great WarEdit
Before the great war, the scientists in Boulder Dome were involved in intense research of the New Plague. When reports of the plague manifesting in Denver emerged many of Boulder's residents fled north to avoid any migrating infected persons. The scientists went into a deep comatose sleep while locking down the Dome in order to preserve their research and prevent infection. As a result they slept through The Great War.
After the Great WarEdit
170 years later, Goddard a scientist with the NCR, discovered the Boulder Dome was still intact. He reports back to Victor Presper, who immediately sets out out investigate. Over the next few years Presper invites or sends scientists and students to the Boulder Dome, where he explains his idea to remake civilization. Those who refuse are put in cold sleep, using technology the original Dome scientists developed to aid space travel.
A few later, after the scientists had been trapped in Boulder Dome as a result of their exposure and subsequent infection to the New Plague, One of the grad students (Paul) discovers the Sleepers in a deep level of the facility – the scientists Presper sent here and put to sleep to help with his new world order.