Lone Star Geyser Trail

Quick facts

Distance Miles: 4.8
Route Type: Out-and-back
Difficulty Level: Easy
Elevation Gain Feet: 0

Trail profile

Distance Miles: 4.8
Route Type: Out-and-back
Difficulty Level: Easy
Elevation Gain Feet: 0
Estimated Time: 2-3 hours if you're fit, 3-4 if you stop for geyser eruptions and photos
Trail Surface: Partially paved asphalt service road transitioning to gravel for the final section
Trail Features: Lone Star Geyser
Firehole River
Geothermal hot springs
Paved service road
Trail Highlights: Lone Star Geyser eruptions (up to 45 feet, roughly every 3 hours) and the scenic Firehole River valley.

Trailhead & access

Trailhead Location: 3.5 miles south of Old Faithful Overpass, just beyond Kepler Cascades Parking Lot
Parking Lot Size: Kepler Cascades Parking Lot—capacity unknown; secondary lot away from Old Faithful central facilities
Parking Fill Time: Summer season fills during peak hours; arrive by 7 AM for reliable parking
Shuttle Required: 0
Shuttle Details: Not required. Trailhead is accessible via personal vehicle from Old Faithful area.

Permits & conditions

Permit Details: Not required.
Fees: $35 entrance fee for private vehicle (valid 7 days); $20 per person on foot/bicycle. No additional trail fee.
Trail Status: Open year-round; road access varies seasonally.
Seasonal Closures: Most park roads open mid-April through early November. Winter travel requires snowmobile or snowcoach from park entrances.

Facilities & rules

Restrooms At Trailhead: 0
Water Sources: Firehole River runs alongside trail—water must be filtered or treated before drinking. No potable water at trailhead.
Accessibility: Wheelchair and mobility device accessible on paved service road portion. Final few hundred feet transition to gravel—accessibility limited.

Safety & strategy

Hazards: Thermal features and boiling water
Toxic gases from geothermal vents
Sun exposure on asphalt
River hazards during snowmelt
Crowds during peak season
Hazard Details: Lone Star Geyser cone and thermal runoff areas are extremely hot and dangerous—barriers exist for a reason. Geyser eruption spray can reach 45 feet. Hydrogen sulfide gas and other toxins are present; stay on marked trail. River crossings may be swift during snowmelt. Full sun on unshaded asphalt creates heat stress risk.
Cell Service: Unreliable to absent. Service depends on location within the basin.
Crowd Level: Moderate to high during peak season (July-August); lighter crowds in spring and fall.
Peak Crowd Times: July-August, midday 10 AM-4 PM. Early morning (before 8 AM) offers better solitude.
Best Season: Spring through fall (mid-April through early November). Summer offers warmest, driest conditions.
Best Time To Visit: Start by 7 AM to secure parking and beat afternoon crowds. Spring through fall offer reliable access (most roads open mid-April to early November). Summer is hot—carry double water. Winter access requires snowmobile or snowcoach; trail may be inaccessible.
Tips Advice: Carry 2L water minimum—full sun on asphalt, zero shade.
Geyser erupts roughly every 3 hours; check times at visitor center to time your arrival.
Paved section is wheelchair-accessible; final section becomes gravel.
Watch for cyclists on the asphalt portion.
Stay behind barriers at thermal features—boiling water and toxic gases kill fast.

More details

Park Area: Upper Geyser Basin
Trail Markers: Well marked and obvious—paved service road is hard to lose.
Dogs Allowed: No. Pets are not permitted on this trail.
Biking Allowed: Yes, on asphalt section only. Cyclists must dismount and walk the final few hundred feet.
Shade Level: Full sun on asphalt service road with minimal tree cover. Wear a hat, apply sunscreen, plan for exposure.
Emergency Contacts: Call 911 (cell service permitting). Ranger support available at Old Faithful area (3.5 miles north).
Map Recommended: 1
Snow Dates: Typically December through March; exact dates vary by elevation and season severity.
Mud Season: April-May during snowmelt; trail may be slippery.
Bug Season: July-September; mosquitoes are active around the Firehole River area.
Insider Tips: Time your hike to catch a geyser eruption—check predicted times at visitor center or online.
The gravel section isn't the end; hike to the cone for the full experience.
Bring a headlamp if hiking late—the service road is exposed after dark.
Spring is muddy but offers fewer crowds.
The Firehole River is scenic—take 10 minutes at Mile 2 for photos.
Family Friendly Notes: Flat and easy enough for families with young children. Thermal hazards require constant supervision—children must stay on trail at all times. Geyser eruption viewing is exciting for kids; timing helps.
Nearby Facilities: Old Faithful area (3.5 miles north) has visitor center, lodging, dining, shops, and gas. Nearest restroom: Old Faithful complex.
Review Summary: Hikers call this the accessible geyser experience—it delivers Yellowstone drama without technical climbing. The paved section feels gentle, but thermal hazards are real and demand constant respect. Crowds can be heavy in summer; early morning or shoulder season (May-June, September) offers better conditions.

Frequently asked questions

Can I do this trail if I'm not in great shape?

Absolutely. It's flat and mostly paved. The challenge is sun exposure and hydration management, not fitness. An average person can do this at any pace.

Is this trail safe to hike alone?

Yes, in daylight. It's well-marked, well-trafficked, and stays near the river. Avoid solo night hikes—the service road is exposed and unmarked after dark.

Will I definitely see a geyser eruption?

Lone Star erupts roughly every 3 hours, but it's not on a clock. You might wait 2-4 hours. Check predicted times at the visitor center before starting. If timing fails, the walk is still scenic.

Do I need special gear for thermal hazards?

No special gear needed. Just stay on the marked trail, obey barriers, and don't touch thermal features. The hazards are obvious and fenced.

How much water should I bring?

Minimum 2 liters. Full sun, high altitude, and minimal shade mean aggressive dehydration. Treat river water with filter or purifier if you need to refill.

Is this good for kids?

Yes, for kids who can walk 4.8 miles and stay on trail without bolting toward steam vents. The flat terrain is kid-friendly; thermal hazards demand constant parental attention.

Can I bike this?

Yes on the paved asphalt section. You must dismount and walk the final few hundred feet. Bikes and crowds mix poorly; consider the popularity before committing.