Geyser Spring

What to expect

Geyser Spring, also listed as Geyser Warm Spring, is not a soaking spring, and it is worth knowing that before you drive all the way up the West Dolores valley. It is a small, round pool of milky turquoise water about the size of a hot tub, sitting among ferns in a side drainage of the San Juan National Forest. Every 30 to 40 minutes or so, gas pushes up from below and the pool starts to churn and spill over into Geyser Creek for 10 to 15 minutes, then settles again. That makes it, by most accounts, the only true geyser in Colorado. It is a quiet, slightly eerie thing to watch rather than a spectacle.

The water runs at about 82°F28°C, so it is warm rather than hot. More importantly, the gas that drives the eruptions is mostly carbon dioxide and hydrogen sulfide. Both are heavier than air and gather just above the water, and the state’s COTREX trail guide warns that they make the oxygen level near the pool dangerously low. Treat this as a place to look from the bank, not a place to get in. The faint rotten-egg smell is the hydrogen sulfide.

The hike itself is a good half-day outing. It starts in a meadow beside the West Dolores River, crosses on a wooden footbridge, and climbs on switchbacks through aspen and spruce before dropping to the pool. The trail passes old mine workings, which are signed and should be left alone.

Getting there

The trailhead is on West Dolores Road (Forest Service Road 535) in Dolores County, about 2 miles south of the Dunton townsite.

• From Dolores: Drive northeast on Colorado 145 up the Dolores River, then turn north onto West Dolores Road. The trailhead is about 19 miles from the highway. The pavement runs out partway, leaving about 8 miles of narrow gravel.
• From Telluride: Allow about 1.5 hours, partly on gravel.

The road is suitable for most passenger cars in good conditions, but it is narrow, washboarded in places and slick after rain. Check conditions with the Forest Service at the Dolores Public Lands Center before you go, especially in spring and late fall.

The Forest Service rebuilt the trailhead in 2014 after a dispute with a neighboring landowner. The trail used to cross private land on a private bridge and an unsafe rock ford; it now starts a quarter mile south, from an improved parking area, and crosses the West Fork of the Dolores on a new wooden bridge. Stay on the signed route and respect the private property around Dunton.

From the lot the trail runs about 1.25 miles each way. Sources put the climb at roughly 500 to 650 feet, with the route between about 8,600 and 9,100 feet in elevation. It crosses Geyser Creek twice. Allow 1.5 to 2 hours round trip, plus however long you wait for an eruption.

When to go

Late spring to October is the practical season. Snow covers the upper trail through much of the winter, and West Dolores Road is a long way to drive on snow. Early summer brings wildflowers in the meadow and higher water in the river. September is the standout month, when the aspen groves on the switchbacks turn gold. Summer afternoons often bring thunderstorms, so start in the morning.

Crowds are rarely a problem. This is a remote corner of the forest and the trail sees light use, though fall weekends are busier.

Rules and etiquette

• No fee is listed for the trailhead or trail.
• Do not swim or soak. Beyond the gas hazard, the pool is small and easily fouled.
• Stay out of the old mines. Forest officials have warned that hydrogen sulfide collects around the mine openings near the trail; dead birds and rodents have been found at one entrance.
• Leashed dogs are allowed on the trail. Keep them away from the pool, where they are closer to the gas layer than you are.
• Pack it out. There are no facilities on the trail.
• Respect private land near the trailhead and around Dunton. The trail was moved specifically to keep hikers off it.

Where to stay nearby

There is no camping on the trail itself. Your options:

• Forest Service campgrounds along West Dolores Road, such as West Dolores and Mavreeso campgrounds, sit beside the river downstream of the trailhead. Check current fire restrictions before you build a fire.
• Dunton Hot Springs, about 2 miles up the road, is a high-end resort in a restored mining ghost town with private hot spring pools. It is a booked-in-advance stay, not a casual stop. See the Dunton Hot Springs listing for details.
• Dolores, back down on Colorado 145, has motels, food and fuel, and is the closest real town. Rico and Telluride are further east over Lizard Head Pass.

Safety notes

• Gas: the biggest risk here is invisible. Do not lean over the water, lie down beside it, or let children or dogs play at the edge. If you get a headache, feel dizzy or lightheaded, move away and uphill right away.
• Mines: hydrogen sulfide around the old mine openings can kill. Obey the warning signs.
• Altitude: the trail is above 8,500 feet. Visitors from low elevation should go slowly and drink plenty of water.
• Remoteness: cell service is limited on West Dolores Road. Tell someone your plan and carry a paper or offline map.
• Weather: afternoon lightning is common in July and August. Be off the switchbacks before storms build.
• Footing: the creek crossings and the area around the pool can be muddy and slick.

Nearby stops worth adding

West Dolores Road is a beautiful drive in its own right, following the river through meadows under the peaks of the San Miguel Mountains. Combine the geyser with a picnic by the river, or continue on to the Lizard Head Pass area on Colorado 145 for big views of the San Juans.