The Great Northern Fort was a massive Alaskan fortification located in the town of Klastok in the Evgenigrad-Klastok Oblast from the early 1870's until it was deconstructed in the mid-1930's. At the prime of its use, it was envisioned as the central staging ground for the Alaskan Army of the East against rogue Indian tribes and later the Americans, and its complex fortifications, raised location and array of cannon made it a nearly impregnable, but eventually unsustainable, location for battle. While its location proved successful in diverging and thinning American positions across 200 miles in 1884, a more concentrated attack in 1885 proved that the fort was unsustainable for long periods of time with a finite amount of food and gunpowder, and the fort was surrendered on September 11, 1885 to the American army, although it was abandoned less than three months later during Arthur Perry's retreat from the devastating losses in the Yukon. The fort stood mostly empty during the early 20th century as Klastok was bypassed by other railroad lines, and was eventually deconstructed as it had become derelict and a home to criminals and suppliers of American bootleggers by the late 1920's. The fort was completely gone by 1934.