Hike to Colorado's Only Geyser on Geyser Spring Trail

Deep in the San Juan National Forest, a moderately challenging trail leads to one of Colorado’s most unusual geological features.

Geyser Spring is widely described as Colorado’s only natural geyser. Don’t expect an Old Faithful-style eruption. This remote spring bubbles like a witch’s cauldron and carries the unmistakable aroma of rotten eggs.

I discovered it while exploring the San Juan Mountains during a fall trip to Cortez.

Getting to Geyser Spring Trail

Geyser Spring Trail is off Forest Road 535, also known as Dunton Road or County Road 38. The trailhead is about two miles south of Dunton Hot Springs.

I turned onto Dunton Road from the Dolores side and drove more than 20 miles. Much of the route was paved, followed by several miles of gravel.

The scenery is spectacular during peak fall color. Golden aspens covered the hillsides, making the drive part of the experience.

The road between Dunton and Highway 145 has narrow stretches, drop-offs and rough sections. A high-clearance vehicle is helpful.

Geyser Spring Trail Stats

Distance: 2.6 miles round trip
Route: Out and back
Difficulty: Easy
Starting elevation: 8,590 feet
Ending elevation: 9,111 feet
Elevation gain: Approximately 520 feet
Trail number: Geyser Spring Trail #648
Best seasons: Summer through fall

The trail is not long, but its remote location and rocky sections add to the adventure.

Hiking to the Geyser

The 1.3-mile trail begins by crossing a small bridge over the West Dolores River. It then climbs gradually through aspens and pines.

Fall color surrounded me during the first section. Golden leaves glowed against the deep-green conifers, and the river added a soothing soundtrack.

Less than a mile into the hike, the trail became rockier near a switchback. This was the steepest section of the route.

I soon smelled sulfur and spotted a small opening with bubbling water. It was a preview of the much larger feature ahead.

After the climb, the trail rolled through tall aspens with expansive views of the surrounding mountains. As I started downhill, I heard water before the trees opened to my first view of Geyser Spring.

Seeing Colorado’s Only Natural Geyser

Geyser Spring does not shoot water high into the air. Instead, gas periodically sends water churning and bubbling across the pool.

The activity often occurs in 30- to 40-minute cycles and can last for approximately 15 minutes. Its water temperature is only about 82 degrees, which is cool compared with many geothermal springs.

During my visit, the geyser bubbled for almost the entire 15 to 20 minutes I spent there. At times, the churning became noticeably more intense.

Between the bubbling water and strong sulfur smell, it reminded me of a witch’s brew. It is strange, fascinating and unlike anything else I’ve seen while hiking in Colorado.

It looks like hot tub, but don’t get in it. Dangerous gases depleting the oxygen at the water’s surface are deadly.

Colorado’s only natural geyser is part of a series of hot springs in the Dolores River watershed. During the mid-Cenozoic Period, about 28 million years ago, intrusions of water into geologic faults were exposed to magma deep within the earth’s crust. The expanding carbon dioxide gas driven by magma heated water is what gives Geyser Spring its geyser characteristics.

A Beautiful Hike Out

The return trip follows the same route. I slowed down to savor the golden aspens, which are always one of my favorite parts of fall in Colorado.

Geyser Spring Trail offers an unusual combination of mountain scenery, fall color and fascinating geology. The hike is moderately challenging without being long, making it easy to pair with a scenic drive through the San Juans.

After the Hike

Afterward, I drove past Dunton Hot Springs and continued the ten miles toward Highway 145. The rough road demands attention, but the scenery had me dreaming about returning for a stay at the luxurious resort.

This trail is remote, quirky and wonderfully Colorado. Just remember that the bubbling pool is for viewing—not soaking.