This paper presents a model of pastoralists, as illustrated by reindeer herders, together with an analysis based on a cross-sectional data set on Swedish reindeer-herding Saami. The intrinsic utility of being an active reindeer herder plays an important role in determining supply. Results show this can lead to unconventional supply responses among pastoralists, and suggest that the probability of a backward-bending supply response increases with stock size. Further analyses confirm that reindeer herders with backward-bending supply curves have significantly larger herds than herders with conventional supply responses. Relaxed externalities from forestry would cause most herders to increase their slaughter.