Seventeen Myodes gapperi (Vigors) (Rodentia: Cricetidae), 13 Peromyscus maniculatus (Wagner) (Rodentia: Cricetidae), 12 Microtus pennsylvanicus (Ord) (Rodentia: Cricetidae), four Zapus princeps Allen (Rodentia: Cricetidae), three Ictidomys tridecemlineatus (Mitchill) (Rodentia: Sciuridae), and eight shrews (Soricomorpha: Soricidae) collected at Blackstrap Lake (BL), and 48 P. maniculatus, 15 Z. princeps, 15 M. pennsylvanicus, and one Sorex monticolus Merriam (Soricomorpha: Soricidae) collected at Saskatchewan Landing Provincial Park (SLPP), in southern Saskatchewan, Canada were examined for ticks. Although no adult ticks were detected on small mammals at either locality, Dermacentor variabilis (Say) (Acari: Ixodidae) larvae (n=144) and nymphs (n=7) were found on four species of small mammal at BL. At SLPP, both D. variabilis larvae (n=71) and nymphs (n=6), and Dermacentor andersoni Stiles (Acari: Ixodidae) nymphs (n=9) were collected from small mammals. Both tick species were present on P. maniculatus and M. pennsylvanicus at SLPP, indicating an overlap in their host range and, hence, the potential for transmission of microorganisms between tick species at sites where they coexist. However, the results of polymerase chain reaction assays used to detect bacteria of the genus Rickettsia da Rocha-Lima (Rickettsiaceae) in ticks, revealed that R. peacockii Niebylski et al. only occurred in nymphs of D. andersoni, whereas no Rickettsia were present in the larvae and nymphs of D. variabilis.