The Bureau of Mines and the Alaskan Division of Geological and Geophysical Surveys have jointly developed a methodology to quantitatively assess the potential for undiscovered but economically recoverable minerals within a mineralized terrane or region. This methodology, referred to as rockval, provides a rigorous procedure for disaggregating the assessment problem into a set of technical judgments that focus on and capture the important geologic, engineering, and economic factors affecting the occurrence and economic viability of mineral resources. The procedure requires geologists and engineers to express their knowledge and opinions in terms of standard geologic and engineering parameters, which are then combined in a simple grade-tonnage format to generate quantitative estimates of regional resource potential. The methodology further provides for the explicit incorporation of uncertainty in the values of the geologic parameters; thus, the assessments are expressed as probability distributions and directly indicate the limitations in the data base and knowledge of the region. Assuming 1983 prices, the total gross recoverable value of mineral resources in the Kantishna Hills area was estimated to range from $375 million to $1,260 million at the 90% confidence level.