Permafrost Tunnel Research Facility

Available to study warm, ice-rich, fine-grained permafrost

U.S. Army Corps of Engineers Research and Development Center (ERDC)
Published Nov. 19, 2012
A split within the permafrost tunnel.

A split within the permafrost tunnel.

Permafrost Tunnel Entry

Permafrost Tunnel Entry

Established in 1963, the Permafrost Tunnel Research Facility, located in Fox, Alaska is part of ERDC's Cold Regions Research & Engineering Laboratory that provides researchers, scientists, and students with a unique source of data in a natural laboratory. The facility is available to assist engineers and scientists to study warm, ice-rich, fine-grained permafrost in situ – allowing time for detailed research and sampling.

A Deep and Rich Exploration Site

The Permafrost Tunnel stands apart from other cold regions research sites by allowing users to make observations both from above and within the permafrost.

The tunnel was excavated into a silt escarpment that illuminates 45,000 years of details about the soil, including organics, bacteria, and bones frozen in place. The high ice content of the syngenetic permafrost consists of ice wedges, segregation ice lenses, reticulate chaotic cryostructures, and thermokarst-cave ice. The tunnel is refrigerated year-round, preserving the site for long-term sampling and in situ research.

Preserving the Past, Predicting the Future

The tunnel’s walls reveal how a sequence of climate shifts have affected the permafrost in central Alaska during and following the last Ice Age, enabling researchers to better predict future climate change effects on permafrost.

Paleontologists are able to view actual remains of animals and plants preserved by the cold, rather than just fossil records. Microbiologists have discovered bacteria trapped in ice within the tunnel, and were able revive it after being frozen for 25,000 years.

The challenge for permafrost engineers is to design long lasting infrastructure on permafrost at low cost. Here, engineers have the ability to test the mechanical properties and deformation sensitivity of these ice-rich soils, and also test methods for detecting ice content of permafrost with geophysical techniques.

The tunnel has also served as a living classroom for hundreds of engineers, scientists, university students, policy makers, and interested members of the public.


The work done by scientists and researchers in the Permafrost Tunnel has led to increased understanding of subjects in several scientific disciplines, including:

  1. Permafrost morphology
  2. Permafrost cyrostructure
  3. Design and construction methods in frozen soils
  4. Geophysical testing
  5. Climate change and permafrost stability
  6. Permafrost physics and chemistry
  7. Cold regions mining technology


  • 650-meter tunnel complex consisting of two horizontal adits, three cross connections and a winze connecting to a large room excavated into a deeper gravel layer down to bedrock


The Permafrost Tunnel is NOT open for public tours, however, we do offer access for research, outreach and education purposes by appointment only.

All tour requests affiliated with the University of Alaska Fairbanks are required to coordinate their tour requests through the Office of the Vice Chancellor for Research, please email or call (907) 474-6000.

Work with Us

Our capabilities and facilities are available to assist you in addressing and solving a variety of cold regions science and engineering challenges. Please consult the facility manager below for facility usage and rates information, which vary depending on the type of activity and support needed. The facility manager can also provide additional documentation.


Alaska Research Office
U.S. Army Engineer Research and Development Center | Cold Regions Research and Engineering Laboratory
Updated 14 March 2024

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