Trail

Snow Pass Ski Trail

Trail
Skiers follow a straight trail through a snowy forest.

Snow Pass Ski Trail is a 4.2-mile winter ski expedition with 700 feet of vertical gain that cuts through dense forest and icy terrain before opening into panoramic views of Swan Lake Flats. The difficulty varies wildly—smooth rolling terrain for 2.2 miles (if you start from Glen Creek), but vicious icy switchbacks with cliff edges elsewhere. Expect encounters with bison and elk. This is a one-way proposition requiring shuttle logistics and serious winter backcountry judgment.

Quick facts

Distance Miles
4.2
Route Type
One-way (with return option)
Difficulty Level
Mixed (Easiest to Most Difficult)
Elevation Gain Feet
700

Trail profile

Distance Miles
4.2
Route Type
One-way (with return option)
Difficulty Level
Mixed (Easiest to Most Difficult)
Elevation Gain Feet
700
Estimated Time
2-3 hours one-way; 4-6 hours round-trip from Glen Creek depending on snow conditions and descent speed
Trail Surface
Skier-tracked snow
Trail Features
  • Heavily forested ascent with steep grades (1.5 miles, 700 ft)
  • Snow Pass saddle (mountain pass)
  • Wide-open views of Swan Lake Flats
  • Icy switchback sections with drop-offs
  • Rolling terrain through open meadow
  • Glen Creek drainage corridor
  • Rustic Falls landmark
Trail Highlights
700-foot ascent through dense forest to Snow Pass saddle, then descent to panoramic vistas of Swan Lake Flats. Option to link to Bunsen Peak Road Ski Trail for extended expedition.

Trailhead & access

Trailhead Location
Glen Creek Trailhead on Swan Lake Flats; or connector from Upper Terrace Loop Ski Trail; or south of Upper Terrace Loop parking area on Mammoth-Norris Road
Shuttle Required
1
Shuttle Details
One-way or round-trip skier shuttles may be offered through park concessionaire. Confirm availability and schedule with Mammoth District Ranger Station before arrival. Winter roads (Mammoth-Norris) are snowpacked; 4WD or chains likely needed for self-drive access.

Permits & conditions

Permits Required
Yes
Permit Details
Service animals require backcountry access permit. Contact Mammoth District Ranger Station or visit https://www.nps.gov/yell/index.htm for application details.
Fees
No trail fee. Yellowstone entrance: $35 (private vehicle, 7 days). Shuttle fee (if used): unknown.
Trail Status
Open (winter season); closed summer (June-October)
Seasonal Closures
Closed when snowpack melts (typically April-May). Reopens with winter snow (typically November-December). Only accessible December-March in most years.

Facilities & rules

Restrooms At Trailhead
0
Water Sources
Melt snow or filter Glen Creek en route; bring backup water capacity of 1+ liter.
Accessibility
Trail difficulty varies by route choice. Glen Creek Trailhead approach: 2.2 miles of relatively flat/rolling terrain. Upper Terrace/Mammoth-Norris routes: steep icy sections with challenging technical difficulty. Not wheelchair accessible; backcountry winter ski experience required.

Safety & strategy

Hazards
  • Icy curves with steep drop-offs
  • Wildlife (bison, elk, bears, wolves)
  • Steep forested grades
  • Cold exposure and wind chill
  • Navigation difficulty in poor visibility or whiteout
Hazard Details
NPS warns: 'Some curves have steep drop-offs and can be hazardous when icy.' Bison and elk frequent the trail; federal law requires 25 yards minimum distance. Bears and wolves require 100 yards. Winter conditions create whiteout risk; visibility and safety change hourly.
Cell Service
Limited to none (backcountry winter conditions)
Crowd Level
Solitude (winter backcountry crowds are minimal; most park traffic is summer)
Best Season
Winter
Best Time To Visit
During stable snow conditions (mid-to-late winter). Start by sunrise to avoid deteriorating afternoon conditions. Check with Mammoth District Ranger Station for snow stability and icing reports before committing.
Tips Advice
  • Winter ski jacket, goggles, and gaiters mandatory—wind chill is brutal at elevation.
  • Carry minimum 1L water (snow is your backup) and high-calorie snacks; cold burns fuel fast.
  • Tighten boot bindings before icy sections—loose equipment means disaster on drop-offs.
  • Make noise constantly—bison and elk use this corridor; give them 25 yards minimum.
  • Check with Mammoth District Ranger Station for recent icing and hazard reports before departure.
  • Bring map and compass; visibility can vanish in whiteout conditions.

More details

Park Area
Mammoth Hot Springs
Trail Markers
Skier-tracked corridor; well-defined in good snow; markers become invisible in storm conditions.
Dogs Allowed
Service animals only (must be leashed; backcountry access permit required)
Biking Allowed
No (winter ski trail only)
Shade Level
Partial (heavily forested for first section and ascent; open terrain after Snow Pass saddle)
Emergency Contacts
911 (life-threatening emergencies); Mammoth District Ranger Station (non-emergency backcountry support via https://www.nps.gov/yell/index.htm)
Map Recommended
1
Snow Dates
December–March (typical winter season; varies by year and elevation)
Mud Season
N/A (winter ski trail only)
Wildflower Peak
N/A (winter trail)
Fall Colors Peak
N/A (winter trail)
Bug Season
N/A (winter trail)
Insider Tips
  • Glen Creek Trailhead offers the mellow entry; don't let 'easiest' fool you—you'll still need solid winter edge control.
  • The Upper Terrace connector descent is the real lung-buster; save your energy.
  • Link to Bunsen Peak Road Ski Trail (south across the road) for a full expedition day.
  • Bison favor the open meadow sections; they're predictable but maintain your 25-yard distance.
  • Check avalanche forecast with ranger station before heading into steeper slopes.
Family Friendly Notes
Only appropriate for experienced winter skiers. Icy drop-offs on some sections mean hand-holding young children not practical in ski gear. Ski ability and cold tolerance are non-negotiable prerequisites.
Review Summary
Winter skiers report the Glen Creek approach is more moderate than feared, but the forested ascent and icy technical sections separate the grit from the tourists. The payoff—open views across Swan Lake Flats and the exhilarating descent—is genuine but demands respect for winter hazards and wildlife encounters.

Frequently asked questions

Is this trail safe for intermediate skiers?

Depends on your route. Glen Creek approach (2.2 miles) is manageable for intermediate skiers with solid winter experience. The Upper Terrace/Mammoth-Norris sections demand expert edge control and icy terrain comfort. Know which trailhead you're using and scout conditions first.

Can we skip the shuttle and do a round-trip from one trailhead?

Yes. Most skiers do this. Glen Creek is the natural out-and-back starting point with the mellow approach. Add 2-3 hours return time if skiing back uphill, depending on fitness and snow conditions.

How many water/food stops are on the trail?

Zero. This is backcountry. Melt snow (bring a lighter) or carry all water from the start. Glen Creek is nearby but filtering in winter is slow. Bring high-calorie snacks—the cold burns fuel fast.

Will we see bison or elk?

Likely. They use this corridor year-round. Keep 25 yards away and never approach. Make constant noise to alert them to your presence. Federal law enforces these distances.

What if conditions are icy?

Turn around. Icy drop-offs kill experienced skiers. NPS flags this hazard for a reason. Check recent conditions with Mammoth rangers; they have real reports. Come back when snow conditions improve.

Do I need avalanche gear?

Not mandated, but smart. This terrain is steep enough for slab avalanches in heavy snow. Check the avalanche forecast (NOAA/park ranger) before going. Beacon, probe, and shovel are survival tools if you trigger one.

Brink of Lower Falls

0.7 miles out-and-back. Steep climb back. The brink of Lower Falls rewards the grit.

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Sources

Editorial review: YourNPGuide Editorial Team. Information is compiled from official sources, verified traveler reviews, and editorial research; no firsthand visit is implied unless explicitly documented. Learn how YourNPGuide works.

Last updated June 2026. Report an issue.