A study of small rodent populations, habitat use, and amounts of small mammal damage to woody-stemmed plants on reclamation areas of Suncor Inc. lease was begun in July 1978 and continued until November 1979. Three species of small rodent were present in these areas; Microtus pennsylvanicus was the most abundant species followed by Peromyscus maniculatus and Clethrionomys gapperi. Microtus pennsylvanicus and P. maniculatus were captured in all study areas, whereas G. gapperi were captured only in an area dominated by natural regrowth of trees and shrubs. A number of other small mammal species such as Mustela erminea, Eutamias minimus, Microsorex hoyi, Sorex cinerius, and Phenacomys intermedius were captured in the reclamation study areas but numbers were extremely limited. Microtus pennsylvanicus and P. maniculatus populations in older reclamation areas were composed primarily of resident, breeding animals, whereas C. gapperi were only seasonally abundant. Microtus pennsylvanicus and P. maniculatus in new reclamation areas were mostly transient animals. Older reclamation areas with dense grass/legume cover appeared to provide highly suitable habitats for M. pennsylvanicus, moderately suitable habitats for P. maniculatus, and poor quality habitats for C. gapperi. New reclamation areas did not appears to provide suitable habitats for any of these three species. Aspects of habitat structure that were associated with small rodent abundance also are discussed. Small rodent damage to woody-stemmed plants was limited in all reclamation areas during 1978 and 1979. Amounts of damage were highest in older reclamation areas with dense grass/legume cover. The close association between grass cover and amounts of damage and between amounts of damage and numbers of M. pennsylvanicus suggests that the high numbers of M. pennsylvanicus in areas of dense grass cover may be associated with the high amounts of damage in these same sites.