OSVUM — Lassen National Forest (2023)

Over-Snow Vehicle Use Map (OSVUM): where snowmobiles and other over-snow vehicles are allowed, and when. Lassen National Forest, 2023 edition. Public domain map from the USDA Forest Service, republished from https://www.fs.usda.gov/r05/lassen/maps-guides. When the forest posts a new edition it shows up here as a free update.