PDFWAC 332-52-420
Snowmobiles.
(1) Where are snowmobiles permitted to travel on department-managed land?
(a) Persons may operate snowmobiles on department managed lands only when there is adequate snow cover to prevent resource damage.
(b) Persons operating snowmobiles may only travel over the snow:
(i) On roads, cut banks, fill slopes, ditches, and trails.
(ii) On designated roads that are part of a groomed snowmobile trail.
(iii) Off of designated roads and trails unless the area is designated or posted closed to snowmobile use.
(c) Persons shall not operate snowmobiles on department-managed lands under any other conditions or in any other locations.
(d) No other motorized vehicle is allowed on a groomed snowmobile trail without prior written authorization from the department.
(2) Any violation of this section is an infraction under chapter 7.84 RCW.