The Permafrost Tunnel is situated near the valley floor of Goldstream Creek, 16 miles north of Fairbanks, Alaska. Permafrost distribution in the Fairbanks area is discontinuous, however the location near Fox, Alaska (see map below) provided continuous permafrost for the excavation of the tunnel. Because of the elevation markers on contour maps such as the one below, the Permafrost Tunnel location was misrepresented for many years as being located on "Hill 456." The notation 456 is actually the elevation, not the name.
|Contour map of the area surrounding the Permafrost Tunnel.
||The tunnel is located in central Alaska; the red square designates the approximate location on the map to the left.
||The tunnel portal during construction.
Placer gold mining along Goldstream Creek in the early to mid 20th century provided an escarpment with which CRREL engineers chose to place the entrance to the tunnel. The portal passes through seasonally frozen soil and it was felt this 10-meter section would require structural support. The permanently frozen soil of the remaining facility has sufficient strength and does not require additional structural support typical of most underground excavations. Excavation was conducted during the winters of 1963, 1964, and 1965.