A former forty-niner , Bradshaw knew that the northern gold mines were rapidly emptying and that miners and other people leaving the area would need a more direct trail from the south across the desert to the new gold strike at La Paz . A former forty-niner , Bradshaw knew that the northern gold mines were rapidly becoming exhausted and that the flood of refugees from the area would need a more direct trail from the south across the desert to the new strike at La Paz .