Upper Klawasi Warm Springs
Upper Klawasi Warm Springs stands at 2,980 feet elevation in the Copper River basin near Valdez, displaying some of Alaska's most extraordinary water chemistry with sodium levels reaching 10,000 milligrams per liter and chloride at 11,000 milligrams per liter. The spring's magnesium concentration of 300 milligrams per liter ranks among the highest recorded.
The spring emerges in a high-altitude landscape where annual precipitation drops to just 21.9 inches and average temperatures plunge to 29.3 degrees Fahrenheit. Snow accumulates heavily at 69.4 inches annually. The setting combines alpine terrain with the rugged Copper River basin's steep valleys and sparse vegetation. This elevation and latitude create an environment where the thermal water provides stark contrast to the surrounding cold.
The spring's unusual chemistry likely reflects deep groundwater circulation through mineral-rich bedrock. The composition—low calcium (6.5 mg/L) but extremely high sodium and chloride—suggests the water has passed through saline deposits or marine-influenced strata. The Copper River basin's complex geology of sedimentary and volcanic rocks creates conditions for this distinctive thermal signature.
Backcountry access requires serious mountaineering skills and expedition planning. The site lies 18,328 meters from Silver Springs Loop Road across unmarked terrain. Winter conditions are severe. Summer offers the only realistic visiting window. No services exist on-site. Visitors must be entirely self-sufficient with proper equipment, navigation tools, and wilderness experience.
Is Upper Klawasi Warm Springs worth visiting?
Best for
- Backpacking adventures
Not ideal for
- Day trips with young children
The water at Upper Klawasi Warm Springs is neutral (pH 7.1). 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).