Sumdum is an abandoned mine and community located at the head of Sanford Cove on the south shore of Endicott Arm, about 8 miles (13 km) southeast of Harbor Island and 55 miles (89 km) southeast of Juneau, Alaska. The mining town had a post office from 1897 to 1942, and was named for the Sumdum Glacier. The Tlingit Indian name reportedly represents the booming sound of ice breaking off from the glacier. The name was first published in 1892 by the U.S. Coast and Geodetic Survey as “Soundon”.
The mine portal was about 1.8 miles (3 km) south-southeast of the abandoned town of Sumdum. The Sumdum Mine was discovered in 1889 and consisted of two veins, the Bald Eagle and the Sumdum Chief. Originally these were separate properties but were consolidated into a single mine in 1899. Most of the mining took place from 1895 to 1903 when the ore bodies were exhausted and diamond drilling was unsuccessful in finding additional ore. The veins were mined from a tunnel 3,500 feet (1067 m) long. From 1895 to 1903, the mine produced 24,000 ounces (680 kg) of gold and about the same amount of silver.
The mill contained 10 stamps and 10 tons (9,072 kg) of rock were milled per day when running at full capacity. A pipe 12,000 feet (3,658 m) in length brought water to Pelton wheels that generated 170 horsepower. A wagon road from the mill together with an aerial tramway to the wharf were used to transport the concentrates. Read more here and here. Explore more of Sumdum here: