I dug up some info HERE
but the link is now password protected...
so here are some other links:
Originally Posted by USFS
Spark Arresters - What is the Law?
California Vehicle Code Section 38366 Spark Arrester Law - Laws and Safety
"CVC 38366. (a) Notwithstanding Section 4442 of the Public Resources Code, and except for vehicles with mufflers as provided in Article 2 (commencing with Section 27150) of Chapter 5 of Division 12, no person shall use, operate, or allow to be used or operated, any off-highway motor vehicle, as defined in Section 38006, on any forest-covered land, brush-covered land, or grass-covered land unless the vehicle is equipped with a spark arrester maintained in effective working order.
(b) A spark arrester affixed to the exhaust system of a vehicle subject to this section shall not be placed or mounted in such a manner as to allow flames or heat from the exhaust system to ignite any flammable material.
(c) A spark arrester is a device constructed of nonflammable materials specifically for the purpose of removing and retaining carbon and other flammable particles over 0.0232 of an inch in size from the exhaust flow of an internal combustion engine or which is qualified and rated by the United States Forest Service.
(d) Subdivision (a) shall not be applicable to vehicles being operated off the highway in an organized racing or competitive event upon a closed course, which is conducted under the auspices of a recognized sanctioning body and by permit issued by the fire protection authority having jurisdiction."
US Forest Service Forest San Bernardino National Forest Order No. 5 - Roads and Trails
Pursuant to 36 CFR 261.50 (a) and (b) each of the following acts are prohibited on the identified areas under my jurisdiction:
4. Operating a vehicle in violation of the California Vehicle Code. 261.54d
Violation of these prohibition is punishable by a fine of not more than $5,000 or 6 months imprisonment or both. See 16 USC 551.
But that is just San Bernardino NF... what about the others?
Originally Posted by Humboldt-Toiyabe NF
To be legal your spark arrestor must have USDA Forest Service approved stamped into it. It also must be in working condition.
So which is it YFF!?!
Well, I think I found my answer over at ThumperTalk:
"There is no nation wide spark arrestor requirements for US Forest Service land."
So I guess each unit can issue their own orders, requiring either a spark arrestor OR a USFS approved (stamped) spark arrestor...