I dont know about in Missagain but I know here the Gov. ran camp grounds are a bit more strict where as the USFS camp ground is not as strict and is usually free to park. When they checked us we didnt get issued tickets or told we couldnt ride or anything. I dont think we even had our spark arrestors in, My 450 with my TRC Yoshi put up 105db the LTZ with its fmf fac. 4 was 101 and a buddies junkie raptor was 103. very well over the legal limit. There is a residential area and camgrounds around Sand Lake here in Oregon, but for that they have the "sound break up area" (covered in trees) around the riding area that is off limits to ride. which seems to help I guess.