Increasing geotechnical activities in subarctic and arctic regions, such as major opencast coal mining, pipeline construction, and alluvial underground mining, call for improved techniques of frozen granular ground disintegration and better control of the breakage processes. The U.S. Bureau of Mines conducted high-pressure water jet cutting experiments on frozen, gold-bearing, granular materials. The objective was to evaluate performance and efficiency in terms of required specific energy for disintegration. The tests were conducted underground during the winters of 1984 and 1985, at the U.S. Corps of Engineers experimental permafrost tunnel near Fox, AK. Testing pressures from 6.9 to 51.8 Mpa (1,000 to 7,500 psi) and flow rates ranging from 0.2 to 3.2 L/s (3.2 to 50 gpm) were used. All testing was performed under actual in situ conditions in a section of frozen auriferous gravel and underlying bedrock. Specific energies needed to cut frozen gravels, the overlying silt, and the partially decomposed bedrock were determined. Furthermore, large holes were drilled in frozen bedrock and gravel to assess the effectiveness of high-pressure water jets in large-volume fragmentation of frozen materials.