36 CFR 261.12: National Forest System roads and trails.

The following are prohibited:

(a) Violating the load, weight, height, length, or width limitations prescribed by State law except by special-use authorization or written agreement or by order issued under § 261.54 of this Chapter.

(b) Failing to have a vehicle weighed at a Forest Service weighing station, if required by a sign.

(c) Damaging and leaving in a damaged condition any such road, trail, or segment thereof.

(d) Blocking, restricting, or otherwise interfering with the use of a road, trail, or gate.

(e) Operating a motor vehicle without a valid license as required by State law.

(f) Operating a motor vehicle while under the influence of an alcoholic beverage or a controlled substance in violation of State law.

(g) Operating a motor vehicle in violation of any State law other than those described in paragraph (e) or (f) of this section.

(h) Operating a vehicle or motor vehicle carelessly, recklessly, or in a manner or at a speed that would endanger or be likely to endanger any person or property.

(i) Operating a motor vehicle in violation of a posted sign or traffic control device.