hese data were collected as part of a field trial to test the efficacy of a sylvatic plague vaccine (see Rocke et al., 2017 for details). Vaccine and control plots were selected randomly from the available sites at each location. At least 1 week and no more than 2 months post-baiting each year, local collaborators captured, marked and sampled prairie dogs for a minimum of 3 trap days. Both plots in a pair were trapped on the same day, and trap effort (number of traps and trap days) between plots of the same pair was similar with few exceptions. Fleas were collected from up to 50 unique prairie dogs from each plot each year. Sex, age, weight, and foot length were recorded for each captured animal. In the laboratory, fleas were identified to species and then pooled by species and sex. Flea pools were tested for the presence of Yersinia pestis using standard or real time PCR. Environmental factors describing temperature and precipitation were obtained from USGS and NOAA databases for each plot at the time of sampling.