Natural Bridge Bike Trail

A natural bridge formation made of rock in a forest.

This is a 2.5-mile mountain bike ride on an old disintegrating paved road followed by a short but steep hiking scramble to a 51-foot natural bridge carved by Bridge Creek. The first half follows forest service roads with minimal elevation gain; the second half pivots to an intense switchback climb with exposed cliff edges and creek crossings. You'll see old-growth forest, Bridge Creek canyon, and rhyolite rock formations. This trail closes until early summer due to bear spawning activity and requires constant vigilance for grizzlies and black bears.

Quick facts

Distance Miles: 2.5
Route Type: Out-and-back
Difficulty Level: Moderate for biking, strenuous for the hiking section
Elevation Gain Feet: 317

Trail profile

Distance Miles: 2.5
Route Type: Out-and-back
Difficulty Level: Moderate for biking, strenuous for the hiking section
Elevation Gain Feet: 317
Estimated Time: 2–3 hours if you pace the hike deliberately and stop for views
Trail Surface: First 2.5 miles: old paved road (mostly disintegrated, fairly level). Hiking portion: natural dirt trail with steep switchbacks and loose rocks.
Trail Features: 51-foot natural bridge (rhyolite rock formation)
Bridge Creek canyon
Old-growth forest
Service road
Creek crossings
Switchback overlooks
Trail Highlights: The 51-foot natural bridge carved through rhyolite rock by Bridge Creek is the payoff. The bridge top offers dramatic views of the creek canyon below and surrounding forest. The hike itself is intense—the switchbacks force a real climbing effort.

Trailhead & access

Trailhead Location: Just south of Bridge Bay Marina off Grand Loop Road
Shuttle Required: 0
Shuttle Details: No shuttle available. Drive directly to trailhead parking near Bridge Bay Marina.

Permits & conditions

Permit Details: General visitors do not need permits. Service animals traveling beyond the paved road portion require a backcountry permit due to wildlife safety concerns. Contact Fishing Bridge Visitor Center for permit details.
Fees: $35 — Entrance - Private Vehicle (7-day pass)
Trail Status: Typically open mid-June through late October
Seasonal Closures: Closed until early summer (typically mid-June) while bears feed on spawning trout in Bridge Creek. Reopening date varies by year; verify at Fishing Bridge Visitor Center before heading out.

Facilities & rules

Restrooms At Trailhead: 0
Water Sources: Bridge Creek provides water, but the banks are slippery and current can be swift, especially after snowmelt. Filter or treat all water. Carry 2–3L in case you cannot safely access the creek.
Accessibility: The paved road section (first 2.5 miles) can be accessed by hand-cycle with care due to disintegrated surface. The hiking portion is steep, natural terrain with scrambling required—not wheelchair accessible. Mountain bikes are recommended for the paved section to handle rough patches.

Safety & strategy

Hazards: Grizzly and black bears
Slippery rocks in creek bed
Uneven and disintegrating paved road surface
Steep cliff exposure on switchbacks
Swift creek current
Hazard Details: Federal regulations require you to stay at least 100 yards (91 meters) from bears and wolves, and at least 25 yards (23 meters) from bison and all other wildlife. Grizzly bears actively forage in this area; black bears are also present. Wear bear spray on your hip belt and make noise constantly. The creek bed rocks are slippery when wet—use caution on all water crossings. The switchback hike to the bridge includes unprotected cliff edges; hand-holding may be required for children.
Crowd Level: Moderate to busy during summer weekends, especially July–August. The proximity to Bridge Bay Marina draws families, but the steep hiking section filters out casual visitors.
Peak Crowd Times: Weekends from 10 AM–3 PM during July and August
Best Season: Summer, Fall
Best Time To Visit: Start by 7 AM during mid-June through late September to beat summer crowds and afternoon thunderstorms. Check Fishing Bridge Visitor Center for exact opening date (typically mid-June after bear spawning season ends). Pack bear spray and two liters of water minimum before 8 AM.
Tips Advice: Wear bear spray on your hip belt—not in a pack. Make noise constantly; ride or hike loudly.
Tighten your bike shoes; the paved section is potholed and unpredictable.
Bring 2–3L of water. Creek water is available but slippery rocks and swift current demand caution.
Mountain bikes recommended but not required for the paved section.
The last 0.5 miles to the bridge are hand-over-hand steep. Test your fitness on the first switchback before committing.
Avoid the trail if thunderstorms are forecast; Bridge Creek will swell and creek bed becomes treacherous.
Do NOT hike beyond the marked Natural Bridge top—the overhang is closed to protect the formation.

More details

Park Area: Lake Yellowstone Area
Trail Markers: Reasonably marked but not heavily signed. The old paved road is obvious; the hiking trail to the bridge is marked with switchbacks and an interpretive exhibit at the base.
Dogs Allowed: No pets are allowed, except service animals with restrictions. Service animals must remain on designated trail and are subject to backcountry permit requirements.
Biking Allowed: Yes, for the first 2.5-mile round-trip on the old paved road. Mountain bikes are recommended but not required. Hiking only beyond the service road junction to the Natural Bridge.
Shade Level: Mostly shaded through the forest on the road section; full sun exposure at the Natural Bridge overlook. Bring a hat and sunscreen for the final push.
Emergency Contacts: Fishing Bridge Visitor Center or nearest ranger station. In an emergency, use your satellite communicator or hike back to Bridge Bay Marina area.
Map Recommended: 1
Snow Dates: No snow expected during typical riding season (mid-June through October)
Mud Season: Early June can be muddy due to snowmelt and bear spawning season closures. Trail is usually dry and rideable by late June.
Insider Tips: The false summit at mile 2 is not the bridge. Keep grinding up the final switchback—the real payoff is another 0.3 miles.
Ride your bike back downhill slowly; the paved road is treacherous with potholes and loose gravel.
Start the hike early (by 6–7 AM) to complete it before afternoon lightning builds over the lake.
The interpretive exhibit at the hiking base explains the geologic formation—worth reading before the scramble to center yourself for exposure.
Bring trekking poles for the descent; the switchbacks are steep and your knees will thank you.
Family Friendly Notes: The paved bike section is family-friendly if children can handle potholed terrain. The hiking portion has steep switchbacks, cliff exposure, and creek hazards. Kids must be supervised closely; hand-holding is mandatory on the final switchback stretch. Not suitable for very young children or those with a fear of heights.
Nearby Facilities: Bridge Bay Marina (1 mi north) has food, supplies, and lodging. Fishing Bridge Visitor Center is 2 miles north and offers bear spray refills, maps, and ranger information. No facilities at the trailhead itself.
Review Summary: Riders report the paved section is easier than expected but the hiking section catches many off guard—the switchbacks are relentless and the cliff exposure is real. The 51-foot bridge is worth the effort. Most hikers rate this as a solid half-day objective with serious bear awareness required. Timing and bear spray compliance are non-negotiable.

Location

Frequently asked questions

Can I do this trail alone?

Yes, but not recommended. Solo travel in active bear country is riskier. If you go alone, make noise constantly, ride with a friend or group if possible, and carry bear spray actively. Tell someone your expected return time.

Do I need a mountain bike or can I use a road bike?

A mountain bike is recommended. The paved road is disintegrating with potholes and loose gravel. Road bikes will struggle with handling; hybrid or gravel bikes work if you ride carefully.

Are there bears on this trail?

Yes. This is active grizzly and black bear habitat. The trail closes early summer during bear spawning season. Always carry bear spray and be alert. Make noise while riding. Stay 100 yards from bears.

How steep is the hiking section?

The final 0.5 miles to the bridge are steep with sharp switchbacks and cliff exposure. Not technical scrambling, but a real lung-buster. Elevation gain is 317 feet compressed into a short distance. Trekking poles help on descent.

What if I can't handle the hiking? Can I just bike?

Yes. The 2.5-mile paved section is rideable on most bikes. Stop at the service road junction and turn around. The hiking portion is optional, but the Natural Bridge is the main attraction.

Is the water safe to drink?

Bridge Creek water must be filtered or treated. Carry 2–3L of water to avoid risky creek drinking. The rocks near the creek are slippery; access is tricky in swift current.