Sylvan Springs
Sylvan Springs reaches 192°F at 7,370 feet elevation in Yellowstone National Park, requiring a 1.7-kilometer hike from the Grand Loop Road. Recent USGS sampling documented acidic water at pH 5.8 with 118 mg/L sodium and notably high iron content at 5,050 µg/L, creating rusty-colored mineral deposits. The spring runs 157 degrees above ambient temperature.
The spring sits in lodgepole pine forest near the base of the Gallatin Mountains in Gallatin County, approximately eight miles south of Mammoth Hot Springs. The surrounding terrain consists of forested ridges with thermal ground creating openings in the canopy where acidic runoff prevents tree growth. At this elevation, annual snowfall reaches 123 inches and precipitation totals 26 inches, supporting dense conifer forest interspersed with thermal features and meadows.
The sylvan name references the wooded setting rather than any specific historical event. The spring has been part of Yellowstone's documented thermal inventory since the early park surveys but remains less visited than roadside features. It continues to function in natural condition under permanent National Park Service protection established in 1872.
Plan visits for July through September when trails are snow-free and accessible. The 1.7-kilometer approach requires moderate fitness and trail-finding skills. Bring topo maps or GPS as the spring sits away from maintained trails. The high iron content creates distinctive orange and red staining that helps locate the feature. Indian Creek Campground, 20 kilometers away, provides the nearest camping option. Watch for thermal ground hazards.
Is Sylvan Springs worth visiting?
Best for
- Observing powerful hot springs
- Overnight camping trips
- Winter soaking with dramatic temperature contrast
Not ideal for
- Casual soaking
The water at Sylvan Springs is slightly acidic (pH 5.8). It is notably rich in iron (iron-rich springs may support circulation).
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Overview Located about eight miles (13 km) south of Mammoth Hot Springs on the road to Norris, Indian Creek Campground—elevation 7,300 feet (2225 m)—sits near the base of the Gallatin Mountains and offers breathtaking views of Electric Peak. The area offers easy access to fishing and hiking. The campground is away from the main road and provides a quieter, more primitive, experience than many other locations. For reservations at the campgrounds managed by Yellowstone National Park Lodges (Fi...