Infestation parameters are presented for 227 ticks, all Ixodes angustus Neumann, collected from individual mammals (n = 531) in southeastern and south-central Alaska from 1996 to 1999. This tick was recovered from 12 of the 19 mammal species examined, with four species of shrews (Sorex spp.), two species of voles [Clethrionomys gapperi (Vigors) and Clethrionomys rutilus (Pallas)], one species of mouse [Peromyscus keeni (Rhoads)], and the red squirrel [Tamiasciurus hudsonicus (Erxleben)] being the most frequently parasitized hosts. Larvae (n = 146) of I. angustus were collected most often, followed by nymphs (n = 50), females (n = 30), and a single male. The leptinid mammal-nest beetle Leptinus occidentamericanus Peck (1male, 5 females) was also recovered from five individual small mammals; three of these were C. rutilus.