Mineral Spring (Lower Klawasi Cone)
Mineral Spring emerges with extraordinarily high salinity at 27,500 mg/L total dissolved solids, making it one of Alaska's most mineral-concentrated thermal features. Despite moderate temperature of 70 degrees Fahrenheit (21°C), the brine-like chemistry creates a remarkable geothermal phenomenon.
The spring flows from Lower Klawasi volcanic cone at 1,840 feet elevation near Valdez in Southeast Alaska's Copper River valley. Visitors access the spring through 4.5 miles of hiking from Silver Springs Loop Road through boreal terrain where annual precipitation totals 17.6 inches, relatively dry by Southeast standards.
This mineral spring forms part of the Lower Klawasi volcanic cone system in the Valdez-Cordova region. The extremely high dissolved solids concentration likely reflects deep circulation through mineral-rich bedrock beneath the volcanic cone, with chloride reaching 12,000 mg/L and sodium at 10,500 mg/L.
Hikers need 4-5 hours roundtrip from Silver Springs Loop Road to reach this geological curiosity. The moderate temperature makes bathing practical, though the high salinity creates unusual buoyancy and requires post-immersion rinsing. Summer access provides optimal conditions for this backcountry thermal destination.
Is Mineral Spring (Lower Klawasi Cone) worth visiting?
Best for
- Mineral-rich therapeutic bathing
The water at Mineral Spring (Lower Klawasi Cone) is slightly alkaline (pH 7.6) with 27500 mg/L total dissolved solids. It is notably rich in magnesium (known for muscle relaxation and stress relief), sodium (supports circulation and skin hydration), and sulfate (traditionally used for skin conditions and inflammation).