What the CDST is

The Continental Divide Snowmobile Trail (CDST) is the long-distance backbone of the regional snowmobile system. It runs from Lander, Wyoming (southeast end) to West Yellowstone, Montana (northwest end) — a total distance of 365 miles, generally paralleling the Continental Divide and actually crossing it four times.

From Island Park, you sit on the western leg of this trail. The section from Island Park west into Idaho and then north to West Yellowstone is roughly 95 miles of the total 365.

The CDST connects to over 600 miles of groomed trail and access to thousands of acres of off-trail powder country. For multi-day snowmobile expeditions in the northern Rockies, this is the trail.

Riding the CDST from Island Park

Access points

The CDST is accessible from several Island Park-area trailheads:

Day rides vs. multi-day

The full 365 miles is a multi-day expedition with fuel and lodging logistics. Most riders do day-loop rides off the CDST: connect to the Two Top loop from West Yellowstone, ride the Sawtelle high country from Island Park, or push toward the Wyoming border on the southern leg.

Direction of grooming

Grooming is maintained cooperatively by the Wyoming State Parks Division (Wyoming section), the U.S. Forest Service (Idaho and Montana sections), and local snowmobile clubs. Grooming priority varies by section — the segments near population centers (West Yellowstone, Island Park) get more frequent grooming than the high-country middle section.

Season

The CDST riding season runs mid-December through March, with grooming continuing into April in big snow years. Excellent spring riding (March through early May) is possible at higher elevations along the trail in years with deep snowpack.

The trail crosses the Continental Divide four times. Each crossing is high country — expect colder temperatures, more wind, and shorter visibility than at the trailheads. Plan accordingly.

Safety considerations

Avalanche terrain

Sections of the CDST traverse or pass below avalanche-prone slopes, particularly in the Centennial Range, the Lionhead area, and the high country between Idaho and Montana. Off-trail riding above the groomed corridor requires avalanche education, beacon/probe/shovel kit, and ideally a guide. Current conditions: Centennial avalanche forecast.

Long distances between fuel

The middle section of the CDST has 40+ mile stretches between settled fuel. Long-distance riders carry extra fuel cans on the sled. Day-loop riders from Island Park or West Yellowstone generally stay close enough that fuel is not an issue.

Cell coverage

None to spotty across most of the trail. Carry a satellite communicator (Garmin inReach or similar) on multi-day rides. Tell someone your plan before going.

Weather

The trail passes through some of the coldest, windiest country in the lower 48. -20°F nights are not uncommon. Multi-day trip planning should account for shelter (warming huts are spaced but not continuous) and breakdown response.

Questions, answered

Do I need a special permit for the CDST?

No, beyond the standard state snowmobile registration sticker (Idaho, Montana, or Wyoming, depending on the section). Yellowstone access from the trail requires the standard NCGSAP permit, separate from the trail itself.

Can I ride the full 365 miles in one trip?

Yes, with planning. Plan 3–5 days depending on conditions, with overnight stops in Pinedale, Dubois (WY) and Henry's Lake or West Yellowstone (MT). Multiple guided expeditions offer the full route.

Is the trail safe for novices?

Sections near population centers are well-suited to novices. Middle-section riding is for experienced groups with appropriate gear and avalanche awareness.

Can I ride one-way?

Yes, but you need to shuttle vehicles. Outfitters in Lander and West Yellowstone arrange one-way shuttles for groups.

Sources & further reading