Blacktail Deer Creek Trail - 7.4mi Strenuous Descent

Two people hike through a field of yellow flowers along the side of a slope.

This strenuous 7.4-mile there-and-back hike descends 1,100 feet through Douglas-fir forest and rolling grassland to a dramatic suspension bridge over the Yellowstone River. The reward is worth the pain: a wild river crossing and intimate views of the canyon below. Expect a punishing descent and a grim climb back out—bring trekking poles and double your water. The trail is shared with horseback riders, so make noise constantly and stay alert.

Quick facts

Distance Miles: 7.4
Route Type: There-and-back
Difficulty Level: Strenuous
Elevation Gain Feet: 1100

Trail profile

Distance Miles: 7.4
Route Type: There-and-back
Difficulty Level: Strenuous
Elevation Gain Feet: 1100
Estimated Time: 4-5 hours if fit, 6-7 if moving cautiously on the descent
Trail Surface: Steep packed dirt with rocky sections, rooty forest passages, loose scree on steeper pitches
Trail Features: Suspension bridge over Yellowstone River
Douglas-fir forest
Blacktail Deer Creek canyon
Rolling grassland
River gorge views
Creek crossing
Trail Highlights: The suspension bridge crossing over the Yellowstone River is the crown jewel—a white-knuckle moment suspended above churning water. The descent offers constant forest-to-grassland transitions and intimate views of Blacktail Deer Creek drainage. The river vista at trail's end justifies every painful step of the return climb.

Trailhead & access

Trailhead Location: 7 miles east of Mammoth Hot Springs on the Grand Loop Road
Shuttle Required: 0
Shuttle Details: No shuttle service available or required

Permits & conditions

Permit Details: No permits required; day-use only
Fees: $35 entrance fee (Yellowstone private vehicle pass, valid 7 days). Trail day-use is free.
Trail Status: Open during designated season
Seasonal Closures: Typically closed November through April due to heavy snow. Check current conditions at nps.gov/yell before departure.

Facilities & rules

Restrooms At Trailhead: 0
Water Sources: Blacktail Deer Creek (filterable) along the descent; Yellowstone River at the bridge. Treat all water. Carry enough to supplement filtered sources.
Accessibility: Rooty, steep, and uneven terrain with packed dirt, loose rock sections, and unstable footing. Not accessible for wheelchairs or those with significant mobility limitations.

Safety & strategy

Hazards: Steep 1,100-foot descent
Horseback riders on shared trail
Loose rock and roots
Slippery when wet
Exposure on suspension bridge
Black bears and grizzlies possible
Hazard Details: The descent is relentless and steep—expect aggressive knee strain on the way down and leg failure on the way up. Loose rock and exposed roots create serious ankle-turning hazard. Horseback riders can appear suddenly around blind curves; move to the side and make noise. The suspension bridge may trigger vertigo in height-sensitive hikers. Black bears and grizzlies are possible, especially near Blacktail Deer Creek; make noise constantly and carry bear spray.
Cell Service: Spotty coverage; do not rely on cellular signal for emergency calls. Use emergency SOS function if available.
Crowd Level: Moderate to heavy; popular trail but the strenuous nature keeps casual hikers away
Peak Crowd Times: July-August midday hours; September-October weekends
Best Season: May through October (Spring, Summer, and Fall)
Best Time To Visit: Late June through September. Start by 7 AM to beat afternoon storms and afternoon heat. May-June offers solitude but trails can be muddy and creek runoff high. September brings fewer crowds, cooler temps, and stable weather. Avoid mornings after heavy rain—the descent becomes slippery and dangerous.
Tips Advice: Bring trekking poles—non-negotiable for the descent to save your knees from permanent damage
Carry 2-3 liters of water minimum; filter at Blacktail Deer Creek midway if needed
Wear sturdy boots with aggressive tread; loose rock and roots will turn your ankles
Make constant noise—the trail is shared with horseback riders and they appear suddenly
Start early; 4-5 hours is optimistic if you're cautious on the descent
The suspension bridge sways—test your nerve on the way down before committing to the turnaround
Tighten your boots before descending; ankle injuries end hikes fast

More details

Park Area: Mammoth Hot Springs District
Trail Markers: Well-marked with cairns and heavily worn tread; impossible to lose your way on this popular route
Dogs Allowed: No pets permitted
Biking Allowed: No; hiking only
Shade Level: Mixed exposure; Douglas-fir forest provides shade for roughly 40% of descent, leaving open grassy slopes exposed to sun and wind for the remaining distance
Emergency Contacts: Call 911 from the trail if signal available. Alert a ranger at Mammoth Ranger Station before departure. In-park radio or ranger contact is the most reliable emergency method.
Map Recommended: 1
Snow Dates: November through April; check nps.gov/yell for current road and trail access updates
Mud Season: May-June; trail can be waterlogged after snow melt and rain events
Fall Colors Peak: September-October; Douglas-fir understory provides changing colors
Bug Season: June-August; mosquitoes and biting insects active near water sources; bring DEET
Insider Tips: The trail is popular with horseback outfitters; mid-morning (9-11 AM) has fewer riders
Most hikers stop at the bridge and turn around; few continue to explore beyond
The descent feels steeper than elevation suggests; control your speed
Water from the creek is safe if filtered; many hikers skip backup water and suffer on the climb out
The return ascent is psychologically harder than the descent; set conservative turnaround time based on when you hit the bridge
Horseback traffic is heaviest Thursday-Saturday; weekday mornings are quieter
Recent Updates: No recent closures or major trail modifications reported. Check nps.gov/yell for current conditions and any seasonal updates.
Family Friendly Notes: Not suitable for children under 12. The 1,100-foot descent is aggressive, unpaved, and technical. The suspension bridge may frighten younger hikers. Hand-holding on the bridge is mandatory. Realistic fitness assessment required.
Nearby Facilities: Mammoth Hot Springs is 7 miles away; offers lodging, dining, fuel, and ranger services. No facilities at trailhead.
Review Summary: Hikers consistently report the descent as steeper and more demanding than anticipated, making the return climb a serious physical test. The suspension bridge is a unique, slightly anxiety-inducing reward that justifies the effort. Most hikers rate it highly but warn newcomers to underestimate neither the descent nor the return ascent.

Frequently asked questions

Is this trail too hard for me?

If you've hiked 8+ miles with 1,000+ feet elevation on uneven terrain before, you can do this. But don't underestimate it. The steep descent is relentless, and the return ascent is brutal. Be brutally honest about your fitness.

Can I do this solo and is it safe?

Yes, done solo regularly and it's safe if you prepare. Bring a whistle, make noise constantly, and tell someone where you're going. The trail is well-traveled enough that help is reachable. Avoid solo hiking at dusk or dawn when visibility drops.

What gear is absolutely essential?

Trekking poles (non-negotiable for the descent), 2-3L water capacity, sturdy boots with aggressive tread, and a headlamp if starting early. Bear spray is recommended. A basic first aid kit for ankle injuries is wise.

What if I'm terrified of heights on that bridge?

Walk it slowly and deliberately. The bridge is engineered to handle horses and hikers; it's safe despite the sway. Look ahead, not down. Some hikers crawl or sit and scoot across—both are valid and safe. You will make it.

When should I turn around if I'm struggling?

If you're not at the bridge by 2 hours from the trailhead, you're behind pace. Reassess your speed. The real test is whether you have energy reserves to climb back up safely. Turn around conservatively and without ego.

Are there bears on this trail?

Yes, black bears and grizzlies are possible, especially in the creek corridor. Make noise constantly, never leave food behind, and carry bear spray. Don't hike alone at dawn or dusk when bears are most active near water.