36 CFR § 261.5 - Fire.
The following are prohibited:
(a) Carelessly or negligently throwing or placing any ignited substance or other substance that may cause a fire.
(b) Firing any tracer bullet or incendiary ammunition.
(c) Causing timber, trees, slash, brush or grass to burn except as authorized by permit.
(d) Leaving a fire without completely extinguishing it.
(e) Causing and failing to maintain control of a fire that is not a prescribed fire that damages the National Forest System.
(f) Building, attending, maintaining, or using a campfire without removing all flammable material from around the campfire adequate to prevent its escape.
(g) Negligently failing to maintain control of a prescribed fire on Non-National Forest System lands that damages the National Forest System.