Ticks and tick-borne diseases are a major concern in the US. Ixodes scapularis (Say) is the vector of multiple bacteria, protists, and viruses that cause human illness, including Lyme disease. While the ecological dynamics of the Lyme disease system have been well-studied in eastern oak forests, much less is known about the drivers and stability of patterns in other forest types and other regions of the United States. Wisconsin is a hotspot for Lyme disease and many emerging tick-borne pathogens. Eighty-eight sites in five maple-dominated forests were characterized by measuring the abundance of ticks and the prevalence of two common pathogens, Borrelia burgdorferi sensu stricto and Anaplasma phagocytophilum, in tick and small mammal hosts over three consecutive years. To identify biotic and abiotic factors that influenced the abundance of ticks and pathogens at both the forest and microgeographic scales, I collected data on the density of host-seeking ticks, the average number of ticks attached to small mammals, the abundance and types of small mammals, and the prevalence of infection at each site. In addition, remotely sensed and field-gathered data were collected, including: soil characteristics, vascular plant community characteristics, camera-trap records of medium and large mammals, earthworm activity, light intensity, and landscape parameters. Questing and on-host tick abundance varied considerably by year and forest. However, relative tick abundance was remarkably consistent across these northern Wisconsin forests. Two species of mice are common to northern Wisconsin forests, Peromyscus leucopus and P. maniculatus. Nearly all prior studies have focused on P. leucopus. I found that these two species play important yet different roles in the transmission and maintenance of tick-borne pathogens. The prevalence of B. burgdorferi was higher in P. leucopus than in P. maniculatus, whereas P. maniculatus was more commonly infected with the pathogen that causes human anaplasmosis. Interestingly, P. leucopus was always found to host more immature I. scapularis ticks than P. maniculatus regardless of forest or year. In summary, my research suggests that mouse species identity and microhabitat characteristics strongly influence the abundance of I. scapularis nymphs, pathogen prevalence, and human risk for tick-borne diseases in northern Wisconsin forests.