The proportion of study sites with <i>Pseudacris crucifer</i> present per year, and the median relative frequency of sites with <i>P</i>. <i>crucifer</i> present across all years, for each study area.

Sites in the St. Croix National Scenic Riverway where P. crucifer was not present in a given year also contained little or no surface water that year during the typical breeding interval for P. crucifer.