Silver Springs 10 mi (16 km) SW Copperville 11 mi (17 km) SW Tazlina 12 mi (19 km) SW Copper Center 12 mi (19 km) SW Anchorage 169 mi (272 km) SW
The Klawasi Group is composed of "three large mud volcanoes located approximately 27 km (17 mi) east of Glennallen near the west slope of the the Pleistocenevolcano, Mt. Drum, in the Copper River Basin of southcentral Alaska. The area is within Wrangell-St. Elias National Park and Preserve" (McGimsey and Wallace, 1999). The three mud volcanoes are named Upper Klawasi, Lower Klawasi, and Shrub. "Shrub rises 340 ft (~100 m) above surrounding terrain and is composed of deposits derived from underlying glaciolacustrine sediments of the Basin (Richter and others, 1998). Low-level mud and minor gas emission has historically been almost constant at the other two mud volcanoes; Shrub [was] virtually inactive for decades with only some minor discharge observed in the mid-1950's (Nichols and Yehle, 1961). During the spring of 1997, Shrub began to vigorously erupt CO2-rich gas and warm saline mud" (McGimsey and Wallace, 1999).
Motyka and others (1989) show how helium and carbon isotope ratios provide good evidence that the Klawasi CO2 is derived from a magmatic intrusive with additional contributions of CO2 from contact metamorphism of deep-seated limestone beds.