Population status of the river otter (Lutra canadensis) in western Oregon [USA] was evaluated by using structural population modeling. Survival and recruitment rates for the female segment of the population were estimated from the age structure of a sample of 113 female otters obtained from trappers during the 1970-71 and 1971-72 trapping seasons. Age was determined from cementum annuli in canine teeth. Annual survival rates were estimated to be 68, 46 and 73% for age-classes 0, 1 and 2-11, respectively. Recruitment was 1.14 female pups/adult female at the beginning of trapping season. Comparison of estimated survival and recruitment rates, by the modeling approach, revealed that the population was stationary.