This mathematical computer model provides a systematic approach for investigating route selection criteria and degree of randomness, provided some infiltration routes are known to the investigator. It has been applied to an area of South Vietnam and adjacent Laos. Since selection criteria usually involve cost, the techniques of dynamic programming have been applied to determine minimum-cost paths, expressed in terms of caloric requirements, with the resulting predicted routes representing the least caloric units between specific start and end points. The cost function is symmetric: uphill and downhill costs when traveling the same direction for equal distances are the same. By comparing deviations of real routes from PREMIR optimal routes, route characteristics other than the optimization criteria can be inferred, such as unknown base camps, villages, or vegetation cover. The model is potentially applicable in determining infiltration route characteristics, barrier and sensor emplacements, and offensive applications.