The bombshelter was originated when ctg867, growing upset over the number of trolls on the gamefaqs Halo 3 board, made a topic about it. Here, he met several people who shared his concerns, including elsquanto, Dejkha, and evildude_93 (These three would later become Global Moderators when the proboard was begun). They looked for an empty board, one that was Halo related, yet safe from troll invasions. They found it in the Halo Triple Pack boards.
This board lasted about a month, and is remembered for clashes with some of the locals, such as Master Ham. These people resented their occupation, and went on to tell known trolls about the existence of the board. This sacrificed the sanctity of the board, and forced the crew to move again.
During this time, numerous aquisitions were made to the bombshelter roster, including Dr. Death, who would later on become an administrator.
The new board was a Half Life board, and the same pattern which had occurred at the Halo Triple Pack board revealed its ugly head. Users such as "The Sarrow" and his alternates began regular invasions of the board. It was around this time that ctg found Littlebro, who had a knack for creating proboards.
ctg had the option of either heading to one of the Marathon boards, as another refuge, but instead elected to have Littlebro create the proboard. The bombshelter was born.