The Mariposa Military Base held vats full of the special F.E.V. Commisioned in 2050 to hold, and develop batches of the F.E.V, the base was kept secret from the public. When the war came, the base was lost, and was found by the founder of the Brotherhood. The stench was deadly, and some of the soldiers lost their pure strain dna, and turned into Super Mutants. Eventually, the base was taken by the mutants. All who entered were killed immediatly. It was horrible.