a line formed by preburning wildland fuels, either adjacent to a control line before igniting a prescribed fire or along a roadway or boundary, as a deterrent to human-caused fires —note 1. a backline is usually made in heavy fuels adjacent to a control line during periods of low fire danger to reduce pressure on holding forces —note 2. a backline denotes a condition in which there is no unburned fine fuel remaining —see fireline This definition last updated 07/17/2008