Lone Star Geyser Trail

Overview

A mellow classic south of Old Faithful, the Lone Star Geyser Trail is an easy, mostly flat out-and-back along the Firehole River to a remote cone geyser. It’s about 5.0 miles total, following a former service road through lodgepole pine with river views and occasional steam vents. It’s far quieter than the front‑country boardwalks, but still delivers a true Yellowstone thermal spectacle.

Route and What You’ll See

Start on wide pavement, then cruise easy gravel as the route parallels the Firehole. You’ll cross a footbridge early and pass a signed junction near Spring Creek before reaching the end of pavement at the Lone Star basin. Stay on the beaten path—the ground around thermal features can be thin. Lone Star’s 12‑foot sinter cone sits in a white apron that makes the eruptions pop against the forested backdrop.

Catching the Eruption

Lone Star erupts roughly every three hours, throwing water 30–45 feet during a major show that lasts around 20 minutes. A minor eruption often happens about 45 minutes before the main event. Timing varies by an hour or two, so check the on‑site log when you arrive and plan your wait. Pro tip: biking the approach makes it much easier to time (and cut your wait) if you’re chasing an eruption window.

Biking, Access, and Regulations

This is one of the few Yellowstone trails open to bikes; cyclists must dismount near the end of the asphalt and walk the final stretch to the geyser. The path is wide with a mostly gentle grade (about 5% or less); surfaces include pavement and gravel with bumps and cracks. The first section’s paving helps, but all‑terrain tires or powered mobility devices can make the gravel sections more comfortable.

Logistics and Facilities

The trailhead sits about 3.5 miles south of the Old Faithful overpass, just beyond the Kepler Cascades parking area. Parking is limited; arrive early and use Kepler Cascades for overflow. There’s a composting toilet at the trailhead; potable water is at the Old Faithful Visitor Center, so fill up before you drive down. Expect mosquitoes in mid‑summer. The route typically hikes best from mid‑spring to early November; it’s groomed for skiing and snowshoeing in winter.

Safety Essentials

Thermal basins demand discipline: stay on the trail and out of runoff channels to protect both yourself and delicate microorganisms. Carry bear spray and give wildlife space—bison use park roads and trails, and bears roam the area. Camping and fires are allowed only in designated backcountry sites with a permit; day hikers don’t need one.

Make It Bigger (If You Want To)

If you want more miles, connect from the Old Faithful area for a moderate ~8.5‑mile loop that includes Lone Star. Strong hikers can continue beyond the geyser toward Shoshone Geyser Basin and Shoshone Lake for a big day (~18.6 miles round‑trip) in true backcountry thermal country. Backpackers use this corridor to reach Shoshone Lake circuits and routes toward Bechler—expect river fords and secure permits for overnights.

Is It Worth It?

For minimal effort, you get a backcountry geyser that puts on a reliable show without the boardwalk crowds. The tradeoff is timing—miss the window and you might wait a while. If you can bring a bike or you’re patient, it’s one of the park’s most rewarding easy outings.