File:Miners thawing frozen ground with steam in an underground gold mine, Third Beach Line, Nome, 1909 (AL+CA 345).jpg

Caption on image: Battery of "sweaters" on "Solo," Third Beach Line, Nome, Alaska. Copyright by A.G. Simmer, 1909. 249 Filed in Alaska--Mining

After the end of the 1900 stampede, the population of Nome remained stable at aproximately 5,000 people each summer through the first decade of the Twentieth Century. Gold production on the Seward Peninsula between 1900-1905 averaged about four to five million dollars per year, most of it coming from the Nome area. As the easily worked beach diggings were exhausted, miners turned their attention inland. Mining activity concentrated on the area between the beach and the foothills behind Nome. The most productive claims were on the famous Third Beach Line, where the miners sunk shafts and drift tunnels through the frozen tundra and ancient, submerged beach lines to get at the gold concentrated at bedrock. Production peaked during 1906 and 1907 at a combined total of almost $15 million. "Sweaters" are the pipes through which water is pumped to thaw permanently frozen ground so that it can be mined. Water at a temperature of from 50 to 60 degrees F (10 to 15.6 degrees C) is pumped through pipes down into the frozen gravel.

• Subjects (LCTGM): Gold miners--Alaska--Nome; Gold mining equipment--Alaska--Nome; Hydraulic mining--Alaska--Nome; Pipes (Conduits)--Alaska--Nome
• Subjects (LCSH): Third Beach Line (Nome, Alaska); Gold mines and mining--Alaska--Nome; Frozen ground--Alaska--Nome