'Reports of a small rodent population outbreak and consequent extensive damage to vegetation of the Trapper Peak-Sundance Mountain burn (56,000 acres, 1967), Kaniksu National Forest, northern Idaho prompted this study. Newspaper accounts and inexperienced observers alleded to small mammal densities of 7000-10,000 per acre. Both deer mice (Peromyscus) and voles (Microtus) were reported to have increased to unusual densities... Study objectives were to evaluate the relative abundance and diversity of small mammals on the burn, obtain a measure of the impact of small mammals on the vegetation, and determine if overt signs of social stress were being manifested. The results reported here did not confirm the presence of unusual densities of small mammals on three areas sampled on the burn in June 1970. However, rodent damage to the shrub stratum had occurred during the previous winter. Virtually no work has been reported on interactions among fires, small mammals, and succession in the northern Rocky Mountains. Public and private wildland management agencies need quantitative data on these interactions to use in developing management policies following extensive forest and range fires.' © by the Northwest Scientific Association. Abstract reproduced by permission.