Over-Snow Vehicle Use Maps (OSVUMs) on the Helena-Lewis and Clark NF

Two snowmobiles travel under a cornice in Red Creek on the Lincoln Ranger District


These maps are gray-scale, letter-sized printable Over-the-Snow Vehicle Use Maps. These maps have a limited purpose. They show the prohibitions and open areas for use of over-snow motorized vehicles on the Helena-Lewis and Clark National Forest pursuant to 36 CFR 212.81. They show established snowmobile routes as well as routes that are open to snowmobiles in areas closed to cross-country snowmobile travel. For detailed information about motorized routes for wheeled vehicles, see the Motor Vehicle Use Maps, which show roads to access snowmobile areas that are open to highway vehicles during certain seasons. We are working on getting maps into GeoPDF format which can be used with various GPS-enabled mobile apps on devices such as cell phones and tablets and can be used to navigate in the forest. Check on your App store for compatible apps. Remember that most areas of the National Forest do not have cell service, so be sure your app works without a cell signal.  Where available, the GeoPDFs are listed below and also on the full OSVUM via a convenient QR code.

*Note: When downloading maps only for use in a navigation application, such as Avenza, please download and read the complete OSVUM, or pick it up at a Helena-Lewis and Clark NF office. The OSVUM contains the complete over-the-snow regulations, definitions, and map legend.




Lewis and Clark-Side

  • Please note that for the Rocky Mountains, Little Belt Mountains, Castle Mountains, Crazy Mountains, and Highwood Mountains only snowmobiles are allowed during the given winter season. No vehicles steered and driven by tracks or with bench seating (such as snow coaches, ATVs and UTVs with 4-track conversion kits) are allowed. Snowmobiles are defined as:

    Snowmobile.  An over-snow vehicle that operates on a track, uses one or more skis for steering, and has handle-bar steering and a seat designed to be straddled by the operator. (FSM 2350.05)

  • In the Big and Little Snowy Mountains snowmobiles, as well as vehicles with snow tracks on them, such as snow coaches and UTVs with conversion kits are allowed as over-snow vehicles, during the dates shown on the OSVUM.

Please be aware that special orders may supersede certain portions of these maps, and certain conditions may warrant temporary special closures to mitigate safety or resource concerns.