Located in a distributary system of Yukon River, heads at Paimiut Slough and flows west to Yukon River, 28 miles northeast of Russian Mission, Yukon-Kuskokwim Delta. (AK-T1)
Local name shown on a manuscript chart of the Yukon River dated 1922; probably so named because the slough was thought to be twelve miles long. (AK-T1)
Paimiut Mountain, Red Mountain,
Ridges:Rivers:Summer Slough, Twelvemile Slough,
Streams:Cities: